Smirnov made his debut in the FIS Cross-Country World Cup on 18 December 1982 at Davos in a 15 km race, finishing in a 17th place.

A very regular and effective cross-country skier, especially in long-distance classic style races, Smirnov took part to the Winter Olympics from 1988 to 1998.

He was one of the leading characters of that Olympics, as his unending rivalry with home ever-winning Bjørn Dæhlie had gained him the affection of the Norwegian audience.

[2] Smirnov headed the bid committee to have Almaty, Kazakhstan, host the 2014 Winter Olympics, a bid that failed to make the short list that was announced by the International Olympic Committee on 22 June 2006.

Smirnov moved to Sweden in 1991 and lives in the city of Sundsvall, where he was a co-founder and co-owner of a local brewery.