He was educated in Sweden.
Gustov was the head of the Leningrad oblast until it was dissolved in October 1993. In 1994, he served as chairman of the Federation Council"s the commonwealth of independent states (Commonwealth of Independent States ) affairs committee. He was elected as the governor of the Leningrad region in September 1996, taking 53% of the votes.
He replaced Aleksandr Belyakov in the aforementioned post.
Gustov served as governor until his appointment as first deputy prime minister on 18 September 1998. He was succeeded by Valery Serdyukov as the governor of the Leningrad region.
Gustov, an independent politician, was one of two first deputy prime ministers in the cabinet of Yevgeny Primakov and he was in charge of regional affairs and the relations with former Soviet republics. Gustov"s tenure lasted until 27 April 1999 when he was removed from post by Russian President Boris Yeltsin.
Gustov was succeeded by Sergei Stepashin in the post.
In the 1999 and 2003 elections Gustov ran for the governorship of the Leningrad region, but he lost both elections. In January 2002 he became a senator at the Federation Council, representing the Vladimir Oblast. He was again the chairman of the council"s Commonwealth of Independent States affairs committee during this period.
Gustov was an anti-Yeltsin figure in the 1990s. Because he was non-communist he did not support for planned economy idea.
He was independent but he was supported by the Communist Party of the Russian Federation.