Medication errors are among the most common medical errors and cause significant morbidity and in some cases mortality. The objective of this article is to review the literature on medication errors in psychiatry. We completed a comprehensive search of both peer- and non-peer-reviewed articles that investigated medication errors in psychiatry. Our primary focus was to examine patient-, provider- and system-related factors that contributed to medication errors. Due to differences in research design and denominators used to determine error rates, the reported prevalence rates of medication errors in psychiatry vary widely. Patient-related factors identified as contributing to medication errors included non-adherence to medication, failure of patients to inform their various care providers about the medications they are taking and symptoms of psychiatric illnesses. Provider-related factors identified as contributing to medication errors were also identified and included clinical practices associated with prescribing, transcription, dispensing, administration and monitoring. Finally, the healthcare system also has a major role to play in reducing medication errors by ensuring seamless continuity of care, mandating medication reconciliation programmes, ensuring adequate clinical pharmacy services and supporting a nonpunitive medication error reporting system. Although the literature raises awareness of these specific contributing factors, there is still a great need for more systematic evaluations of the problem including root cause analysis. Medication errors in psychiatry have been studied almost exclusively in the inpatient setting and thus little is known about the incidence and significance in outpatient and community settings.