| IAEA | : | International Atomic Energy Agency |
| IALL | : | International Association of Low Libraries |
| IAMIC | : | International Association of Music Information Centres |
| IAML | : | International Association of Music Libraries |
| IARIL | : | International Association of Rural and Isolated Libraries |
| IAS | : | Individual Article Supply |
| IASA | : | International Association of Sound Archives |
| IASLIC | : | Indian Association of Special Libraries and Information Center |
| IASSIST | : | International Association for Social Science Information Service and Technology |
| IATUL | : | IInternational Association of Technological University Libraries |
| IBB | : | International Business Machine |
| IBBY | : | International Board on Books for Young People |
| IBI | : | Intergovernmental Bureau of Information |
| IBICT | : | Brazilian Institute for Information in Science and Technology |
| IBM | : | International Business Machine |
| ICA | : | Information Center for Aeronautics |
| ICAR | : | Indian Council of Agricultural Research |
| ICCR | : | Indian Council of Cultural Relation |
| ICDM | : | Information Center for Development Policy Modeling |
| ICDR | : | International Center for Diarrheal Diseases Research |
| ICHR | : | Indian Council of Historical Research |
| ICMR | : | Indian Council of Medical Research (New Delhi) |
| ICPR | : | Indian Council of Philosophical Research |
| ICs | : | Integrated Circuits |
| ICSSR | : | Indian Council for Social Science Research |
| ICSU | : | International Council of Scientific Unions |
| ID | : | Identification |
| IDA | : | Integrated Digital Access |
| IDC | : | International Documentation Centre |
| IDRC | : | International Development Research Centre |
| IDSA | : | Institute of Defense Studies and Analysis |
| IEC | : | International Electrotechnical Commission |
| IEEE | : | Institute of Electrical and Electronics Engineers, Inc. |
| IFD | : | International Federation for Documentation |
| IFDO | : | International Federation of Data Organizations |
| IFIS | : | International Food Information Service |
| IFLA | : | International Federation of Library association and Institution |
| IHAC | : | Information Highway Advisory Council |
| IIB | : | International Institute of Bibliography; Institut International de Bibliographie (Now FID) |
| IIC | : | International Institute for the Conservation of Art and Historic Artefacts |
| IIC-GC | : | International Institute for Conservation – Canadian Group |
| IIR | : | Intelligent Information Retrieval |
| IIS | : | Institute of Information Scientists |
| IK | : | Indigenous Knowledge |
| ILA | : | Indian Library Association |
| ILL | : | Inter Library Loan |
| ILSA | : | Indian Library Science Abstract |
| IM | : | Information Management |
| INB | : | Indian National Bibliography |
| INFLIBNET | : | Information & Library Network |
| INFOTERRA | : | International Referral System for environmental Information |
| INIS | : | International Nuclear Information System |
| INIST | : | Institut de l’Information Scientifique et Technique |
| INPADOC | : | International Patent Documentation Service |
| INSAT | : | Indian National Satellite |
| INSDOC | : | Indian National Scientific Documentation Center |
| IPA | : | International Publishers Association |
| IPC | : | Institute for Paper Conservation |
| IR | : | Information Retrieval |
| IRC | : | Internet Relay Chat |
| IRM | : | Information Resource(s) Management |
| IRPTC | : | International Register of Potentially Toxic Chemicals |
| IRS | : | Information Retrieval System |
| IRTC | : | Industrial Toxicology Research Center |
| IS | : | Information Superhighway |
| ISA | : | Indian Standardization Association |
| ISBD | : | International Standard Bibliographic Description |
| ISBN | : | International Standard Book Number |
| ISDN | : | Integrated Service Digital Network |
| ISDS | : | International Serials Data System |
| ISA | : | Indian Standard Institution |
| ISI | : | Institute for Scientific Information |
| ISMN | : | International Standard Music Number |
| ISO | : | International Standard Organization |
| ISONET | : | International Organization for Standardization Network |
| ISRN | : | International Standard Recording Number |
| ISRO | : | Indian Space Research Organization |
| ISSN | : | International Standard Serial Number |
| IT | : | Information Technology |
| ITC | : | International Translations Centre |
| ITIB | : | Industrial and Technological Information Bank |
| ITU | : | International Telecommunications Union |