Objective: This meta-analysis was conducted to investigate the effects of mindfulness-based stress reduction (MBSR) on the mental and physical health status of various cancer patients. Methods: Ten studies (randomized-controlled trials and observational studies) were found to be eligible for meta-analysis. Individual study results were categorized into mental and physical variables and Cohen’s effect size d was computed for each category. Results: MBSR may indeed be helpful for the mental health of cancer patients (Cohen’s effect size d 5 0.48); however, more research is needed to show convincing evidence of the effect on physical health (Cohen’s effect size d 5 0.18). Conclusion: The results suggest that MBSR may improve cancer patients’ psychosocial adjustment to their disease. Copyright r 2008 John Wiley & Sons, Ltd.