| International Centre of Insect Physiology and Ecology | QF0 | Kenya |
| International Collective in Support of Fishworkers | NL1 | Netherlands |
| International Crops Research Institute for the Semi-Arid Tropics | QX0 | India |
| International Development Research Centre | QD0 | Canada |
| International Engineering Academy | GED | Georgia |
| International Food Policy Research Institute | QB0 | United States of America |
| International Fund for Agricultural Development | XF1 | Italy |
| International Institute of Tropical Agriculture | QU0 | Nigeria |
| International Journal of Advanced Biotechnology and Research Press | IMC | India |
| International Journal of Innovative Approaches in Agricultural Research | TRE | Turkey |
| International Livestock Research Institute | KE3 | Kenya |
| International Maize and Wheat Improvement Centre | QY0 | Mexico |
| International Potato Center | QP0 | Peru |
| International Rice Research Institute | QR0 | Philippines |
| International Scientific Publications | BG1 | Bulgaria |
| International Union of Forestry Research Organizations | QO0 | Austria |
| International Water Management Institute | QL0 | Sri Lanka |
| IPB University | ID1 | Indonesia |
| Iranian Environmental Mutagen Society | IRB | Iran (Islamic Republic of) |
| Iranian Fisheries Science Research Institute | IRW | Iran (Islamic Republic of) |
| Iranian National Institute for Oceanography and Atmospheric Science | IRX | Iran (Islamic Republic of) |
| Iranian Research Organization for Science and Technology | IRQ | Iran (Islamic Republic of) |
| Iranian Society for Ornamental Plants | IRL | Iran (Islamic Republic of) |
| Iranian Society of Ichthyology | IR2 | Iran (Islamic Republic of) |
| Islamic Azad University | IRF | Iran (Islamic Republic of) |
