Including time spent on police investigations, Mavrodi served his full four-and-a-half-year term behind bars.
A crowd of journalists was waiting for him as he emerged from the Matrosskaya Tishina prison, but he was whisked away by security guards without answering any questions.
Activists from the Rossiya Molodaya (Young Russia) movement pelted the car with sour cream, and a placard hung outside the detention center addressed to Mavrodi read: "The people's court is waiting for you."
Mavrodi, who is believed to have diverted some $1.5 billion worth of private investments through the scheme, was placed in custody pending trial in 2003. However, he was formally convicted of fraud only in late April of this year.
A Moscow district court ruled that Mavrodi must also pay 20 million rubles ($774,000) in compensation to jilted MMM investors, as well as a 10,000-ruble fine (about $390).
The Chertanovsky Court said he was proved to have cheated 10,000 investors out of their money during the scheme's heyday in 1992-1994, although that the actual number of those affected could be in the millions.
Analysts say the scheme succeeded largely thanks to a massive advertising campaign, with soap-like television commercials telling the story of a man-on-the-street who turns into a millionaire after putting his modest savings into MMM shares.
Mavrodi was jailed on tax evasion charges after the MMM pyramid collapsed in 1994, prompting thousands of cheated investors to take to the streets in protest. But he was set free the following year to run for parliament.
He secured immunity from prosecution by winning a seat in the State Duma, parliament's lower house, only to lose his mandate a year later. He then went into hiding, and police spent seven years trying to track him down before his arrest in 2003.
