Benteke drew a blank against Aston Villa at the weekend but has scored four goals in his last six Premier League games.
Vieira believes the 30-year-old Belgium international is benefiting from being more involved in the game and hopes that trend continues against Leeds at Elland Road on Tuesday evening.
“I’m really pleased with his form at the moment,” Vieira said. “He’s playing really well and working really hard for the team.
“Most importantly he’s scoring goals and he’s playing with a lot of confidence. I think the way that we play, the amount of possession we have allowed him to touch the ball more and create more chances.
“I think the fact we want to play higher up the field allowed him to be more involved in the game and I think that suits him.
“I think as well the fact that we have (Odsonne) Edouard and JP (Jean Philippe-Mateta) that brings out the best in him because he maybe needed the competition around him to challenge him.”
Benteke scored 17 goals in his first season at Palace following a £27million move from Liverpool, but then managed just six across the next three seasons and 10 in the most recent campaign.
“He’s an international player, he’s been scoring goals in the Premier League and he’s got the experience to be one of the leaders in this team,” former Arsenal midfielder Vieira added.
“I still want him to do even more for the team because he’s got the potential and the quality to do it and we have to be more and more demanding of him.”