President Vladimir Putin signed a law late last year cancelling the 7 November holiday that used to mark the anniversary of the 1917 revolution and replacing it with the Day of People's Unity, a 4 November celebration of the end of Polish intervention in 1612.
Communists and their allies planned to march down Moscow's main street in the afternoon of Monday and demonstrate near a monument to Karl Marx.
Communist leaders have said they expect more people to come out than in recent years for rallies nationwide, galvanised by the cancellation of the holiday.
A message on the Communist party's website said marches and rallies would be held "despite the anti-people, bourgeois authorities' hypocritical ... prohibition of proletarian holidays".
About 2500 people gathered in the Pacific Coast city of Vladivostok. NTV television showed what appeared to be a crowd of at least 500 people in the Far Eastern city of Khabarovsk, holding red flags under a wet snow, and what it said were about 200 people who demonstrated in Krasnoyarsk
One carried a portrait of Lenin. Renamed the Day of Reconciliation and Accord after the Soviet collapse, the 7 November holiday - marked for years by massive parades and displays of military hardware in Red Square - became an occasion for communists and others nostalgic for Soviet times to take to the streets.
In a poll conducted by the respected Levada Centre, 63% of respondents opposed the decision to scrap the 7 November holiday. The 14-17 October poll of 1600 people nationwide had a margin of error of plus or minus three percentage points.
A poll said a majority want the
7 November holiday to remain
On Monday morning, veterans, soldiers and cadets marched on Red Square to mark the anniversary of a parade of Soviet troops heading off to the front in 1941, when Nazi forces were a few dozen miles from Moscow.
Forty to 50 of about 100 surviving participants in the 1941 parade marched on Monday, NTV reported.
"It's our tradition. You walk on Red Square and remember how you walked there in '41," one veteran, whose name was not given, told NTV.
He said that "even when only one person is left, we will still walk on Red Square".
The Day of People's Unity, part of Putin's ongoing effort to boost national pride and patriotism, was marked for the first time on Friday with calls for unity in the multi-ethnic country by a government that also allowed marches by nationalists who urged the expulsion of foreigners.