[3] Al-Sarraj assumed the office of Mayor of Gaza in 2019 after being selected by the city's Hamas-led administration.

Fatah, the political party that dominates the Palestinian Authority in the West Bank, denounced the selection process, although it eventually reconciled with Al-Sarraj.

[5][6] Later in 2019 he announced that he was working on a campaign to get Gaza residents to sort their garbage, and was hoping that a private company could be found to recycle it.

[6] After the 2021 conflict with Israel, Al-Sarraj announced the "We Will Rebuild It" campaign to fix damage caused by the war.

[6] In June of that year, he was honoured by Fatah's Democratic Reform Movement for his work and effectiveness on rebuilding Gaza, with the presentation of the "Shield of Loyalty".