At two Olympic tournaments Sergey Kovalenko played in 15 games and scored 60 points. With the USSR team, he won a bronze medal at the 1970 World Championships in Yugoslavia, and also won gold and bronze medals at the 1969 European Championships in Italy and 1973 in Spain, respectively. From 1969-75 Kovalenko played for Stroitel, Kyiv, twice winning a bronze medal at the USSR Championships with them. In 1975, a conflict arose with the club’s management and he was removed from the team and the league, but with the help of coach Aleksandr Gomelsky Kovalenko returned to basketball and moved to the CSKA club, playing with them until 1980, and winning five Soviet titles.
At the end of his 15-year playing career, Sergey Kovalenko returned to Kyiv. In the early 90s he was an assistant coach for one of the strongest basketball clubs in the USSR – SKA Kyiv. After the collapse of the Soviet Union and the change in the economic situation, Kovalenko worked for a construction company, where he climbed the entire company ladder – from security guard to deputy director. He then organized his own business selling wholesale building materials.