A systematic review of the literature on telephone or internet-based support for smoking, alcohol use or gambling was performed. Studies were included if they met the following criteria: The design being a randomized control trail (RCT), focused on effects of telephone or web based interventions, focused on pure telephone or internet-based self-help, provided information on alcohol or tobacco consumption, or gambling behavior, as an outcome, had a follow-up period of at least 3 months, and included adults. Seventy-four relevant studies were found; 36 addressed the effect of internet interventions on alcohol consumption, 21 on smoking and 1 on gambling, 12 the effect of helplines on smoking, 2 on alcohol consumption, and 2 on gambling. Telephone helplines can have an effect on tobacco smoking, but there is no evidence of the effects for alcohol use or gambling. There are some positive findings regarding internet-based support for heavy alcohol use among U.S. college students. However, evidence on the effects of internet-based support for smoking, alcohol use or gambling are to a large extent inconsistent.