Konstantin Koltsov played for teams such as "Yunost", Minsk's "Dynamo", "Severstal", "Ak Bars", "Spartak", and other Russian clubs. He spent time with the NHL's Pittsburgh Penguins from 2002 to 2006, appearing in 144 games (ranking 7th among Belarusian hockey players), scoring 12 goals, and providing 26 assists.
Representing the Belarus national team, Koltsov played in 123 matches, scoring a total of 55 points (34 goals and 21 assists). Since 2017, he transitioned into coaching, most recently serving as an assistant coach for "Salavat Yulaev" in Ufa, Bashkortostan.