The men's keirin in cycling at the 2000 Summer Olympics was contested by 20 cyclists.
A keirin race consisted of eight laps of the track, or 2 kilometres (1.2 mi).
The top two riders in each heat (six overall) advanced to the next round, while the other fourteen cyclists competed in the first repechage.
The first round repechage consisted of three heats of four to five riders each.
The second round consisted of two heats, with the twelve cyclists split into groups of six.