BACKGROUND: The magnitude of the efficacy of anti-tumour necrosis factor (TNF) therapy in preventing and treating postoperative Crohn's disease recurrence has yet to be determined. METHODS: We searched MEDLINE, the Cochrane Library, and EMBASE. The primary endpoints, and clinical and endoscopic recurrence, were analysed using the Mantel-Haenszel and DerSimonian and Laird methods. RESULTS: Nine controlled trials (n=362) that evaluated the efficacy of anti-TNF therapy in preventing (n=7) or treating (n=2) postoperative recurrence were included. Anti-TNF therapy was more effective at preventing (n=6) endoscopic recurrence than the control arms (odds ratio 0.05; 95% confidence interval 0.02-0.13, P<0.0001; NNT=1.9). Anti-TNF therapy was more effective at preventing (n=5) clinical recurrence than the control arms (odds ratio 0.10; 95% confidence interval 0.05-0.21, P<0.0001; NNT=2.4). Anti-TNF therapy was more effective than control arms at treating endoscopic postoperative recurrence (n=2; odds ratio 16.64; 95% confidence interval 2.51-110.27, P<0.004; NNT=2.3). Neither heterogeneity nor publication bias was observed. CONCLUSION: Anti-TNF agents may be more effective in preventing clinical and endoscopic postoperative Crohn's disease recurrence than control treatment (thiopurines or mesalamine). Efficacy in treating postoperative Crohn's disease recurrence will require further investigation. Large randomised controlled trials are awaited.