The man, identified as Yevgeny Shutov, a businessman born in 1973 in the city of Kazan, was put on a wanted list a year ago after a series of rapes committed in the region in 2003-2012.
The assaults were made on girls and young women aged 15-25. The attacker threatened them with a knife when they entered their apartment blocks, forcing them to go to the top floor.
Investigators concluded that all such attacks were committed by one person.
A number of manhunt activities were carried out but the suspect was only arrested Monday morning after a man called the authorities to report he saw the suspect in Kazan. Police detained Shutov soon after the call.