Abstract This systematic review and meta-analysis evaluates the effectiveness of computerised cognitive behavioural therapy (CCBT) as a low intensity intervention for common mental health disorders (CMHD), and investigates some potential moderators of these effects. A metaanalysis was conducted on 49 randomised controlled trials comparing CCBT to other therapies (n = 24) and waiting list controls (n = 25), across the range of CMHD. Results indicated an overall mean effect size of g = 0.77 (95 % CI 0.59–0.95) in favour of the CCBT trial arms. CCBT was found to be significantly more effective than both waitlist and active control conditions. The mean age of study sample and type of control group both significantly moderated this effect. No further measured variables, including guidance were found to moderate this effect. These findings indicate that CCBT can be an effective low-intensity intervention for CMHD and support the implementation of CCBT within the stepped-care context. Limitations of this review, and implications for theory, research and practice are discussed.