The objective of this systematic review is to investigate the efficacy of educational interventions, relating to psychotropic medications, for consumers with a mental health disorder. This review included only randomized controlled trials that compared the effects of various educational interventions on knowledge retention, compliance to medication and treatment, incidence of relapse, and insight into illness in patients aged 18 years and over with a mental disorder. Twenty-one trials met the quality criteria and were included in the final analysis. Patients who were provided with education demonstrated a significant increase in the level of knowledge and compliance compared with those who were not. However, there was no difference in the incidence of relapse and insight in those who were provided education. A structured education session using both written and verbal methods followed by discussion of the contents is demonstrated to be effective. The evidence suggests that consumers who were provided multiple education sessions had greater knowledge gains in the short term (up to 1 month); however, the effectiveness of multiple sessions in the long term (2 years) is inconclusive. The review provides evidence that multiple education sessions are better than single education sessions in improving knowledge relating to medications and insight into illness. Evidence from the trials demonstrates that structured educational interventions delivered at frequent intervals are useful as part of the treatment programme for people with a mental illness. More well designed and reported randomized studies investigating the efficacy of education are urgently needed.