Background: There is increasing concern about the time young people spend in sedentary behaviour ('sitting time'), especially with the development of attractive home-based electronic entertainment. This may have deleterious health effects. Purpose: To ascertain, through a meta-analytic review, whether interventions targeted at reducing sedentary behaviours in young people are successful. Method: ERIC, MedLine, PsychInfo, SportDiscus and the Cochrane Library databases were searched up to 2010. Titles and abstracts of identifi ed papers were examined against inclusion criteria. Included papers were coded by three researchers. Results: 17 papers, including 17 independent samples (N=4976), met the inclusion criteria and were analysed. There was a small but signifi cant effect in favour of sedentary behaviour reduction for intervention groups (Hedges' g = ? 0.192; SE = 0.056; 95% CI = ?0.303 to ?0.082; p = 0.001). Moderator analyses produced no signifi cant between-moderator results for any of the intervention or study characteristics, although trends were evident. Conclusion: Behaviour change interventions targeting reductions in sedentary behaviour have been shown to be successful, although effects are small. More needs to be known about how best to optimise intervention effects