Background: The ‘Smoke-Free Class competition’ (SFC) is a school-based smoking prevention programme including commitment not to smoke, contract management and prizes as rewards broadly implemented in Europe. Objectives: To meta-analyse (randomised) controlled trials on the effects of SFC on current smoking at latest follow-up in adolescents. Methods: A systematic review of articles using MEDLINE and the Cochrane Library was conducted. The study selection included randomised controlled trials and controlled trials with follow-up assessment that investigated the efficacy of SFC on current smoking in students participating in SFC compared to non-participating students. Independent extraction of articles was performed by both authors. Results: Of 24 records identified, five fulfilled the inclusion criteria. These studies were conducted in three European countries (Finland, The Netherlands and Germany) and recruited 16,302 students altogether. A random effects meta-analysis of these five studies revealed a pooled risk ratio of 0.86 (95% CI 0.79–0.94; z = 3.44, p = 0.001) on current smoking at follow-up by participation in the competition. Conclusion: SFC appears to be an effective tool in school-based smoking prevention.