 In the 100m backstroke event, he earned a silver medal at the European Short Course Swimming Championships 1999 in Lisbon, Portugal and a bronze medal at the 2000 European Aquatics Championships held in Helsinki, Finland.As of 2012, Büyükuncu holds national records in 50m, 100m and 200m backstroke events set in 2009.He has been a Turkish national team member for more than 25 years.