"Talking about a contract extension...the club had made me an offer at the end of last season, I have refused and at the end of the season I will leave the club," Villas-Boas said when pressed on his future at a press conference reported by Zenit's official website.
"But in any case we will continue to work hard, we need to score points, to catch up with those ahead of us, to try to perform successfully in the Champions League."
Villas-Boas, 37, was appointed coach of Zenit in March 2014 and led the club to the Russian title last season.
However, the future of the former Porto, Chelsea and Tottenham Hotspur boss had been up in the air after he was handed a six-match ban earlier this month for pushing an official during Zenit's defeat to Krylia Sovetov Samara.
He has previously said he asked Zenit to release him from his contract at the end of last season but the club refused.
Villas-Boas also saw Zenit lose striker Salomon Rondon, one of their key players, to West Bromwich Albion in the summer after limitations were introduced on the number of foreign players allowed to play in the Russian Premier League.
Zenit are third in the Russian table, six points behind leaders CSKA Moscow, and are in Group H of this season's Champions League, in which they will come up against Gent, Lyon and Valencia.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ