Smertin has previously played for Dinamo Barnaul, Zarya Leninsk-Kuznetski, Uralan Elista, Lokomotiv Moscow, Girondins Bordeaux, and Chelsea. He has been capped over 40 times for Russia, including the 2002 World Cup and Euro 2004 and he was awarded the captaincy in June 2004.
Smertin was taken from Bordeaux to Chelsea by Claudio Ranieri in August 2003 for £3.45m, before spending a loan spell at Portsmouth during the 2003-04 season. After some impressive performances at Fratton Park, most notably in Pompey's 1-0 victory over Manchester United Smertin returned to London after Ranieri had been succeeded by José Mourinho. He then joined Charlton on loan for the 2005-06 season prior to his Chelsea contract being terminated in January 2006, which allowed him to return home and sign a four-year contract with Dynamo Moscow.