[2] Mustafaiev started swimming in 2008 in Sevastopol, Ukraine as part of a rehabilitation regime for a weak back and hand.

[2] In 2011, Mustafaiev made his national team debut and was a member of the Ukrainian delegation at the 2011 IPC European Swimming Championships in Berlin, Germany.

[2][3] Mustafaiev was one of three Ukrainian athletes competing at the 2012 Summer Paralympics from the Crimea region, with the other two including fellow swimmer Dmytro Kryzhanivskyi and shooter Olga Mustafaieva .

[8][9][10] In Montreal for the 2013 IPC Swimming World Championships, Mustafaiev claimed gold in the men's 50 freestyle S4 with a time of 37.96 seconds.

[11][12] He won a silver medal in the men's 100 freestyle S4, losing to Slovenia's Darko Đurić by half a third of a second with a time of 1:27.56 to Duric's 1:27.27.