Chamakh, 28, was photographed smoking a shisha pipe after last weekend's 2-1 Premier League defeat at Queens Park Rangers, and he has not exactly been in red-hot form on the pitch this season.
He has started only seven matches for Arsenal this season and his only goal in a total of 17 appearances came in the 4-3 defeat at Blackburn Rovers last September.
He has not started a match since the FA Cup win over Leeds United in January and Wenger appeared unimpressed over last week's photograph when he spoke to reporters at the club's training ground at London Colney on Friday.
"It's not the best thing to do," said Wenger. "Will he stay at club next season? It's too early to say. We want him to focus completely - without smoking.".
Arsenal, who are currently third, play second-placed Manchester City in the Premier League at home on Sunday.
Wenger said it was still too soon to say whether midfielder Jack Wilshere will play for Arsenal this season, or for England at the European Championships.
The 20-year-old has not featured at all because of an ankle injury which required surgery and Wenger said: "We try to keep the hope alive for him and without taking too many risks.
"That means we adapt day to day, to manage him, to improve his physical state and get him fit as quickly as we can without taking too big a risk, which means when he has pain we stop him."
He was far from optimistic about Wilshere's chances of playing in the Euros for England in June either, explaining: "To go to a big competition without having played at all is impossible.
"In the next four or five weeks we will know more and the next three weeks will be decisive. A player who wants to play in June would have to be competitive at the end of April."
