Background: The health benefits of physical activity and exercise are well documented and these effects could help people with schizophrenia. Objectives: To determine the mental health effects of exercise/physical activity programmes for people with schizophrenia or schizophrenia-like illnesses. Search strategy: We searched the Cochrane Schizophrenia Group Trials Register (December 2008) which is based on regular searches of CINAHL, EMBASE, MEDLINE and PsycINFO. We also inspected references within relevant papers. Selection criteria: We included all randomised controlled trials comparing any intervention where physical activity or exercise was considered to be the main or active ingredient with standard care or other treatments for people with schizophrenia or schizophrenia-like illnesses. Data collection and analysis: We independently inspected citations and abstracts, ordered papers, quality assessed and data extracted. For binary outcomes we calculated a fixed-effect risk ratio (RR) and its 95% confidence interval (CI). Where possible, the weighted number needed to treat/harm statistic (NNT/H) and its 95% confidence interval (CI), was also calculated. For continuous outcomes, endpoint data were preferred to change data. We synthesised non-skewed data from valid scales using a weighted mean difference (WMD). Main results: Three randomised controlled trials met the inclusion criteria. Trials assessed the effects of exercise on physical and mental health. Overall numbers leaving the trials were similar. Two trials (Beebe 2005 and Marzaloni 2008) compared exercise to standard care and both found exercise to significantly improve negative symptoms of mental state (Mental Health Inventory Depression: 1RCT, n=10, MD 17.50 CI 6.70 to 28.30, PANNS negative: 1RCT, n=10, MD -8.50 CI -11.11 to -5.89). No absolute effects were found for positive symptoms of mental state. Physical health improved significantly in the exercise group compared to those in standard care (1RCT, n=13, MD 79.50 CI 33.82 to 125.18), but no effect on peoples' weight/BMI was apparent. Duraiswamy 2007 compared exercise with yoga and found that yoga had a better outcome for mental state (PANNS total: 1RCT, n=41, MD 14.95 CI 2.60 to 27.30). The same trial also found those in the yoga group had significantly better quality of life scores (WHOQOL Physical: 1RCT, n=41, MD -9.22 CI -18.86 to 0.42). Adverse effects (AIMS total scores) were, however, similar. Authors' conclusions: Results of this Cochrane review are similar to existing reviews that have examined the health benefits of exercise in this population (Faulkner 2005). Although studies included in this review are small and used various measures of physical and mental health, results indicated that regular exercise programmes are possible in this population, and that they can have healthful effects on both the physical and mental health and well-being of individuals with schizophrenia. Larger randomised studies are required before any definitive conclusions can be drawn.