| instrument | instrument |
| Instrument dęty | Wind instrument |
| Instrument dęty drewniany | Wood |
| instrument ekonomiczny | economic instrument |
| instrument finansowy | financial instrument |
| Instrument klawiszowy | Keyboard |
| instrument muzyczny | instrument |
| Instrument perkusyjny | Percussion instrument |
| instrument polityczny | policy instrument |
| instrument polityki środowiskowej | environmental policy instrument |
| instrument strunowy | stringed instrument |
| instrument zarządzania gospodarczego | economic management instrument |
| instrumentariuszka | scrub nurse |
| Instrumenty pochodne | Derivative |
| instynktowny | instinctive |
| instytucja | institution |
| instytucja edukacyjna | educational institution |
| instytucja kulturalna | cultural facility |
| instytucja użyteczności publicznej | public institution |
| instytucja zajmująca się ochroną przyrody | nature conservation organisation |
| instytucjonalizacja | institutionalisation |
| instytut | institute |
| Instytut Badań Ciężkich Jonów w Wixhausen | Gesellschaft für Schwerionenforschung |
| Instytut Badań Społecznych | Institute for Social Research |
| Instytut Butantan | Instituto Butantan |
| Instytut Camõesa | Instituto Camões |
| Instytut Cervantesa | Instituto Cervantes |
| Instytut Chrystusa Króla | Institute of Christ the King Sovereign Priest |
| Instytut Dobrego Pasterza | Institute of the Good Shepherd |
| Instytut Estoński | Estonian Institute |
| Instytut Gallupa | The Gallup Organization |
| Instytut Języka Czeskiego | Czech Language Institute |
| Instytut Karolinska | Karolinska Institutet |
| Instytut Konfucjusza | Confucius Institute |
| Instytut Maxa Plancka Molekularnej Biologii Komórki i Genetyki | Max Planck Institute for Molecular Cell Biology and Genetics |
| Instytut Nauki Weizmanna | Weizmann Institute of Science |
| Instytut Oceanografii imienia Scripps | Scripps Institution of Oceanography |
| Instytut Pamięci Narodowej - Komisja Ścigania Zbrodni przeciwko Narodowi Polskiemu | Institute of National Remembrance |
| Instytut Pasteura | Pasteur Institute |
| Instytut Prawa Międzynarodowego | Institut de Droit International |
| Instytut Roslin | Roslin Institute |
| Instytut Santa Fe | Santa Fe Institute |
| Instytut Schillera | Schiller Institute |
| Instytut Stiekłowa | Steklov Institute of Mathematics |
| Instytut Unii Europejskiej Studiów nad Bezpieczeństwem | European Union Institute for Security Studies |
| Instytut Warburga | Warburg Institute |
| Instytuty świeckie | Secular institute |
| Insubrowie | Insubres |
| Insula | Insulae |
| insulina | insulin |
| Insulinooporność | Insulin resistance |
| Insulinopodobny czynnik wzrostu | Insulin-like growth factor |
| Insurekcja kościuszkowska | Kościuszko Uprising |
| Insurekcja warszawska | Warsaw Uprising |
| Insziri | Inchiri |
| Inta | Inta |
| Integer overflow | Integer overflow |
| integracja | integration |
| Integracja społeczna | Social integration |
| Integralizm | Integralism |
| integralny | integral |
| Integrated Services | Integrated services |
| Integrated Taxonomic Information System | Integrated Taxonomic Information System |
| Integrated Truss Structure | Integrated Truss Structure |
| Integryny | Integrin |
| Intel | Intel Corporation |
| Intel Core | Intel Core |
| Intel Core Microarchitecture | Intel Core |
| Intel GMA | Intel GMA |
| Intel XScale | XScale |
| Intel-Action | Intel-Action |
| intelektualista | thinker |
| intelektualny | intellectual |
| inteligencja | intelligence |
| Inteligencja społeczna | Social intelligence |
| Inteligentny agent | Intelligent agent |
| Intelligence Community | United States Intelligence Community |
| Intellipedia | Intellipedia |
| intencja | intention |
| Intendenci we Francji | Business officer |
| intensywna hodowla zwierząt | intensive animal husbandry |
| intensywna terapia | intensive care |
| intensywne uprawa i hodowla zwierząt | agriculture and cattle industry |
| intensywnie | intensely |
| intensywność | intensity |
| intensywny | intensive |
| Inter Bratysława | FK Inter Bratislava |
| Inter Zaprešić | NK Inter Zaprešić |
| Interactive Fiction | Interactive fiction |
| Interactive Voice Response | Interactive voice response |
| Interahamwe | Interahamwe |
| interakcja | interaction |
| Interakcja człowiek-komputer | Human-computer interaction |
| Interakcja społeczna | Social interaction |
| Interakcjonizm symboliczny | Symbolic interactionism |
| interaktywny | interactive |
| Interas-AE Wisaginia | Interas-AE Visaginas |
| InterBase SQL | InterBase |
| INTERCAL | INTERCAL |
| Intercity-Express | InterCityExpress |
| InterCityExpress | InterCityExpress |
| Intercrosse | Intercrosse |
| intercyza | marriage articles |
| interdyscyplinarny | interdisciplinary |
| interes | interest |
| interesować | interest |
| interesujący | interesting |
| Interface Definition Language | Interface description language |
| Interfax | Interfax |
| interfejs | interface |
| Interfejs graficzny | Graphical user interface |
| Interfejs tekstowy | Text user interface |
| interfejs użytkownika | user interface |
| Interferencja | Interference |
| Interferencja RNA | RNA interference |
| Interferometr Macha-Zehndera | Mach-Zehnder interferometer |
| Interferometr Michelsona | Michelson interferometer |
| Interferometr Sagnaca | Sagnac effect |
| Interferometria wielkobazowa | Very Long Baseline Interferometry |
| Interflug | Interflug |
| interglacjał | interglacial |
| Interglacjał eemski | Eemian interglacial |
| Intergovernmental Panel on Climate Change | Intergovernmental Panel on Climate Change |
| Interior | Interior |
| interkalibracja laboratoriów | interlaboratory comparison |
| Interkosmos | Intercosmos |
| interkreatywność | intercreative |
| Interlaken | Interlaken |
| interlingua | Interlingua |
| Interlingwistyka | Interlinguistics |
| interlokutor | interlocutor |
| Internacia Esperanto-Muzeo | Department of Planned Languages and Esperanto Museum |
| Internacional Porto Alegre | Sport Club Internacional |
| Internal Revenue Service | Internal Revenue Service |
| internalizacja kosztów zewnętrznych | internalisation of external costs |
| International Amateur Radio Union | International Amateur Radio Union |
| International Association of Athletics Federations | International Association of Athletics Federations |
| International Auxiliary Language Association | International Auxiliary Language Association |
| International Boxing Federation | International Boxing Federation |
| International Color Consortium | International Color Consortium |
| International Cricket Council | International Cricket Council |
| International DeeJay Gigolo Records | International DeeJay Gigolo Records |
| International English Language Testing System | IELTS |
| International Football Association Board | International Football Association Board |
| International GNSS Service | Global Navigation Satellite System |
| International Hockey League | International Hockey League |
| International Motorsports Hall of Fame | International Motorsports Hall of Fame |
| International Nonproprietary Name | International Nonproprietary Name |
| International Nuclear Event Scale | International Nuclear Event Scale |
| International Organization for Standardization | International Organization for Standardization |
| International Phonetic Association | International Phonetic Association |
| International Police Association | International Police Association |
| International Standard Audiovisual Number | International Standard Audiovisual Number |
| International Standard Book Number | International Standard Book Number |
| International Standard Serial Number | International Standard Serial Number |
| International Taekwon-Do Federation | International Taekwondo Federation |
| International Tennis Federation | International Tennis Federation |
| Internationalized Resource Identifier | Internationalized Resource Identifier |
| internauta | internaut |
| Internazionali Femminili di Tennis di Palermo | Internazionali Femminili di Palermo |
| internet | Internet |
| Internet Architecture Board | Internet Architecture Board |
| Internet Archive | Internet Archive |
| Internet Assigned Numbers Authority | Internet Assigned Numbers Authority |
| Internet Exchange Point | Internet Exchange Point |
| Internet Explorer | Internet Explorer |
| internet kablowy | cable internet |
| Internet międzyplanetarny | Interplanetary Internet |
| Internet Protocol Television | IPTV |
| Internet Research Task Force | Internet Research Task Force |
| Internet Service Provider | Internet service provider |
| Internet Society | Internet Society |
| internetowy | internet |
| internetowy system obsługi | internet search service |
| Interneuron | Interneuron |
| Internowanie ukraińskich obywateli Kanady | Ukrainian Canadian internment |
| internować | intern |
| Interpol | Interpol |
| interpolacja | interpolation |
| Interpolacja funkcjami sklejanymi | Spline interpolation |
| interpretacja | interpretation |
| Interpretacja kopenhaska | Copenhagen interpretation |
| Interpreter | Interpreter |
| interpretować | interpret |
| Interpunkcja | Punctuation |
| InterRail | Inter Rail |
| Interrex | Interrex |
| interrogacja | interrogation |
| interseksualizm | intersexuality |
| Interstate Highway System | Interstate Highway System |
| Intertekstualność | Intertextuality |
| Interwał | Gap |
| interwencja | intervention |
| interwencja na lądzie stałym | intervention on land |
| Interwencja NATO w Afganistanie | War in Afghanistan |
| interwencja w krajobraz przyrodniczy | intervention in nature and landscape |
| interwencjonizm | interventionism |
| interwenient | intervener |
| Interwiki | InterWiki |
| Interwizja | Intervision |
| Inti-Illimani | Inti-Illimani |
| intifada | intifada |
| Into The Labyrinth | Into the Labyrinth |
| intonacja | intonation |
| intonować | intone |
| Intragna | Intragna |
| intramarginalny | intramarginal |
| Intranet | Intranet |
| intratny | lucrative |
| introdukcja | introduction |
| introdukcja gatunków roślin | introduction of plant species |
| introdukcja gatunków zwierząt | introduction of animal species |
| introligator | bookbinder |
| introligatornia | bindery |
| Intron | Intervening sequence |
| introspekcja | introspection |
| Introwersja i ekstrawersja | Extraversion and introversion |
| Intrusion Prevention System | Intrusion-prevention system |
| Intruzja | Plutonite |
