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 . At the 2012 London, 31-year-old Mustafaiev won gold in the 50 metre freestyle S4 event with a time of 38.26 seconds. He had several other events on his London swimming program including the 100m freestyle, 50m backstroke and 200m freestyle races in London. He finished eighth and last in the 50m backstroke final with a time of 52.51 seconds. This time was slower than the heats, where he swam a time of 51.92. Following the 2012 Games, he was awarded the Order of Merit for his sporting achievements.