BACKGROUND: People who suffer from severe mental disorder experience high rates of unemployment. Supported employment is an approach to vocational rehabilitation that involves trying to place clients in competitive jobs without any extended preparation. The Individual placement and support (IPS) model is a carefully specified form of supported employment. OBJECTIVES: 1. To review the effectiveness of supported employment compared with other approaches to vocational rehabilitation or treatment as usual.2. Secondary objectives were to establish how far:(a) fidelity to the IPS model affects the effectiveness of supported employment,(b) the effectiveness of supported employment can be augmented by the addition of other interventions. SEARCH METHODS: We searched the Cochrane Schizophrenia Group Trials Register (February 2010), which is compiled by systematic searches of major databases, handsearches and conference proceedings. SELECTION CRITERIA: All relevant randomised clinical trials focusing on people with severe mental illness, of working age (normally 16 to 70 years), where supported employment was compared with other vocational approaches or treatment as usual. Outcomes such as days in employment, job stability, global state, social functioning, mental state, quality of life, satisfaction and costs were sought. DATA COLLECTION AND ANALYSIS: Two review authors (YK and KK) independently extracted data. For binary outcomes, we calculated risk ratio (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. For continuous data, we estimated mean difference (MD) between groups and its 95% (CI). We employed a fixed-effect model for analyses. A random-effects model was also employed where heterogeneity was present. MAIN RESULTS: A total of 14 randomised controlled trials were included in this review (total 2265 people). In terms of our primary outcome (employment: days in competitive employment, over one year follow-up), supported employment seems to significantly increase levels of any employment obtained during the course of studies (7 RCTs, n = 951, RR 3.24 CI 2.17 to 4.82, very low quality of evidence). Supported employment also seems to increase length of competitive employment when compared with other vocational approaches (1 RCT, n = 204, MD 70.63 CI 43.22 to 94.04, very low quality evidence). Supported employment also showed some advantages in other secondary outcomes. It appears to increase length (in days) of any form of paid employment (2 RCTs, n = 510, MD 84.94 CI 51.99 to 117.89, very low quality evidence) and job tenure (weeks) for competitive employment (1 RCT, n = 204, MD 9.86 CI 5.36 to 14.36, very low quality evidence) and any paid employment (3 RCTs, n = 735, MD 3.86 CI -2.94 to 22.17, very low quality evidence). Furthermore, one study indicated a decreased time to first competitive employment in the long term for people in supported employment (1 RCT, n = 204, MD -161.60 CI -225.73 to -97.47, very low quality evidence). A large amount of data were considerably skewed, and therefore not included in meta-analysis, which makes any meaningful interpretation of the vast amount of data very difficult. AUTHORS' CONCLUSIONS: The limited available evidence suggests that supported employment is effective in improving a number of vocational outcomes relevant to people with severe mental illness, though there appears to exist some overall risk of bias in terms of the quality of individual studies. All studies should report a standard set of vocational and non-vocational outcomes that are relevant to the consumers and policy-makers. Studies with longer follow-up should be conducted to answer or address the critical question about durability of effects.