The present membership of the Bank consists of 57 countries. The basic condition for membership is that the prospective member country should be a member of the Organization of the Islamic Cooperation (OIC) . The IsDB Board of Governors has the authority to set the terms and conditions on the subscription and payment to the capital of the Bank. The cumulative capital subscription from the Initial to the 5th General Capital Increase and the shareholding position of the IsDB member countries as at Gregorian financial year end are as follows:-

Country Capital Subscription ($M) Percentage to total capital (%)
Saudi Arabia 11,896.80 23.50%
Libya 4,771.66 9.43%
Iran 4,174.63 8.25%
Nigeria 3,874.52 7.66%
United Arab Emirates 3,799.49 7.51%
Qatar 3,632.36 7.18%
Egypt 3,579.65 7.07%
Kuwait 3,500.00 6.92%
Turkey 3,263.84 6.45%
Pakistan 1,285.59 2.54%
Algeria 1,285.59 2.54%
Indonesia 1,137.95 2.25%
Malaysia 823.08 1.63%
Bangladesh 509.96 1.01%
Yemen 258.62 0.51%
Morocco 256.69 0.51%
Sudan 232.95 0.46%
Jordan 219.76 0.43%
Oman 142.55 0.28%
Iraq 135.05 0.27%
Cameroon 128.36 0.25%
Brunei 128.36 0.25%
Niger 90.17 0.18%
Burkina Faso 90.17 0.18%
Gabon 54.58 0.11%
Kazakhstan 54.00 0.11%
Azerbaijan 50.92 0.10%
Mali 50.92 0.10%
Senegal 47.81 0.29%
Guinea 45.85 0.09%
Tunisia 36.40 0.07%
Lebanon 35.77 0.07%
Mauritania 35.77 0.07%
Bahrain 25.88 0.05%
Kyrgyz 25.84 0.05%
Gambia 25.84 0.05%
Maldives 25.84 0.05%
Mozambique 25.84 0.05%
Uganda 24.63 0.05%
Benin 20.80 0.04%
Palestine 19.55 0.04%
Syria 18.49 0.04%
Togo 18.16 0.04%
Tajikistan 18.16 0.04%
Sierra Leone 18.16 0.04%
Uzbekistan 13.44 0.03%
Cote D'Ivoire 13.02 0.03%
Comoros 13.02 0.03%
Afghanistan 9.93 0.02%
Chad 9.77 0.02%
Albania 9.23 0.02%
Suriname 9.23 0.02%
Turkmenistan 4.96 0.01%
Guinea Bissau 4.96 0.01%
Djibouti 4.96 0.01%
Somalia 4.96 0.01%
Guyana 2.50 0.01%