Ismail lived for the most part in Salamia, where he died after bequeathing the office of Imamate to his son Muhammad. According to "al- Usul wa'l Ahakam" by Hatim bin Imran bin Zuhra (d. 498/1104) that, "Ismail had sent his dais to all parts and ordered him (Muhammad) to administer the oath in his name according to the custom of all preceding Imams. When his death drew near, he appointed as his heir, his son Muhammad who showed great perfection."
The predeseased tradition assigns Ismail's death in 145/762, but "Dustur al-Munajjimin" (comp. 450/1056) places it in 152/769. According to the Ismaili tradition, Ismail died in 158/775, and was interred in Salamia. Besides Muhammad, he had a son called Ali, who was born in 130/748 and a daughter, Fatima.