After manager Arsene Wenger warned him that he "completely disagreed" with the midfielder's behavior, the England man accepted his error and pledged it will not happen again.
Gunners manager Arsene Wenger declared on Friday that he "disagreed completely with that behavior" and, despite previous claims that the England international was holding the cigarette as part of a "dare", the 21-year-old accepts responsibility for the error.
"I made a mistake," Wilshere told the club's official website. "Players make mistakes. I'm not a smoker.
"I spoke with the boss and he asked me what happened, I explained to him, we sorted it out and he put me in the team and hopefully I repaid him [by scoring against West Brom]. It's not [going to happen again]. I'm not a smoker so I think that will be my last one."
Wenger had warned his young star that "when you are a footballer you are an example and you do not do things to damage your health... it can damage your reputation as well" but maintained Wilshere would remain a key player as long as he learned from the experience.