Although most individuals with schizophrenia are unemployed, plentiful evidence suggests that work rehabilitation is effective for this population. Yet, there have been only 11 published randomized controlled trials of work rehabilitation interventions for people with severe mental illness. We review these 11 studies, 9 of which were trials examining Individual Placement and Support (IPS) or supported employment (SE) interventions. Outcomes strongly favored the experimental groups in terms of the percentage of participants who worked at any point during the studies (weighted mean effect size = 0.66). In the 5 investigations comparing IPS/SE to conventional vocational rehabilitation services, 51% of the participants receiving IPS/SE worked competitively, versus 18% of those in the comparison groups (weighted mean effect size = 0.79). This effect size may be a useful benchmark for future trials. Further investigations should examine individual differences as predictors of response, to identify modifiable versus nonmodifiable factors that yield better outcomes.