There are currently fifty-six countries belonging to the OIC, with a number of other countries accorded observer status.

In fostering cooperation the OIC, like the entire Muslim world, has faced many challenges. In the course of King Fahd’s reign, the OIC has had to contend with the Iraq–Iran War, the Gulf War and Israel’s persistent abuse of the Palestinians and periodic assaults on Arab nations. It has not always been possible to achieve the unity which the OIC charter calls for but, throughout, the Kingdom of Saudi Arabia has followed King Fahd’s principle of seeking peace with justice whenever possible by diplomacy.