This article characterises the social support received by a large sample of smokers attempting to stop and the relationship between this and the outcome of their attempt. A survey was conducted of 928 smokers attending a group-based program. Smoking among colleagues and a perception of having someone to turn to predicted outcome at the end of treatment, 4 weeks from the quit date (Odds ratio [OR] = 0.81, p = .008 and OR = 1.31, p = .003 respectively) Among those who abstained for the first week, smoking among colleagues and the frequency with which they had been offered cigarettes predicted outcome at the end of treatment (OR = 0.81, p = .04 and OR = 0.73, p = .01 respectively). There were no significant social support correlates of cessation for 26 weeks. Social support has a role to play in the short-term, but in the context of a group-based treatment program appears not to be related to long-term success.