After the start of the Great Patriotic War, he, on September 29, 1941, voluntarily joined the ranks of the Red Army and was sent to the Baku School of Anti-Aircraft Artillery. In October 1942, after completing an accelerated training course, Lieutenant Aghahuseynov was appointed commander of the control platoon of the 2nd Battery of the 160th Separate Anti-Aircraft Artillery Battalion in Arkhangelsk. He participated in repelling enemy air raids on Arkhangelsk and Severodvinsk. He also participated in the Vistula–Oder offensive and the Battle of Berlin.