While he was still in his final year at the institute, he began his surgical career as a subordinator in the Department of Hospital Surgery.

After being demobilized from the army in 1945, he was accepted as an intern at the Faculty of Surgery of the Azerbaijan Medical Institute, and in April 1946 was appointed Assistant to the Department.

Completed his thesis on "Complex treatment of purulent pleurisy with long-term use of vacuum-therapy", defended in April 1953.

He was the author of up to 60 scientific articles and in 1957 was elected associate professor of the Department of "Faculty Surgery" at the Azerbaijan Medical Institute.

In order to assist the population of rural areas of Azerbaijan, Garayev repeatedly participated in medical brigades, in addition to his pedagogical activity in the department he served as chief surgeon of the Baku region in 1959 and chief surgeon of the Ministry of Healthcare of the Azerbaijan SSR in 1961–1964.