UN peace envoy Staffan de Mistura described the pullout as a "significant development" for the talks that began in Geneva yesterday in the latest push to end the five-year conflict, but Western leaders were more cautious.
"We hope (this) will have a positive impact on the progress of the negotiations," de Mistura said in a statement.
President Vladimir Putin yesterday ordered the "main part" of his forces out of the war-torn nation but the Kremlin denied it was trying to pressure its long-time ally President Bashar al-Assad.
State media broadcast live footage of flag-waving crowds greeting pilots out of their aircraft at a military base in southwest Russia as a brass band played.
Russia will, however, keep a contingent at its air and naval bases in Syria and a senior military official suggested Moscow's planes could continue striking targets.
"It is still too early to speak of victory over terrorism. The Russian air group has a task of continuing to strike terrorist targets," deputy defence minister Nikolai Pankov was quoted as saying by Russian news agencies at the Hmeimim base in Syria.
Hopes for a breakthrough in Geneva remained remote, with both sides locked in a bitter dispute over Assad's future as the conflict entered its sixth year.
De Mistura was expected to hold his first official meeting with the opposition High Negotiations Committee (HNC), which has repeatedly said that Assad cannot be part of Syria's political future.
The regime insists his removal is a "red line".
Kremlin spokesman Dmitry Peskov said it was "not possible" to infer that the Kremlin was angered by Assad's perceived inflexibility.