Ample evidence documents that supported employment is an effective strategy for improving the vocational outcomes of persons with schizophrenia and other severe mental illnesses. However, a significant amount of clients receiving supported employment services work little or not at all. With respect to factors that may influence the work outcomes of persons participating in supported employment programs, cognitive functioning appears to be potentially important. Cognitive impairment in persons with severe mental illness (SMI) is strongly correlated with functional adjustment in the community and has been shown to be correlated with work, both contemporaneously and prospectively. Studies have demonstrated that clients who did not receive the full benefits of supported employment had more deficits in executive functioning, memory, and psychomotor speed than those clients who had better work outcomes.