On October 24, 1949, he was appointed governor and mayor of Istanbul, succeeding Lütfi Kırdar (in office 1938–1949). Gökay served in this post until November 26, 1957. He introduced price controls on staple foods in Istanbul to protect low-income residents. The municipality of Istanbul founded Migros Türk in 1954 as a joint venture with Swiss Migros, initially operating (like its counterpart in Switzerland) via sales trucks. Gökay opened up the area outside of the Walls of Istanbul for urbanization. He also initiated the foundation of around fifty schools in Istanbul. During his term of office, he was nicknamed "Küçük Vali" (literally ) for his small height, and was a favorite figure depicted in cartoons as such. He was blamed for his passive behavior during the Istanbul riots on September 6–7 in 1955, and was tried before the military tribunal on Yassıada after the 1960 coup d'état.