Partial adherence and nonadherence to medication continue to be problems in the treatment of patients with schizophrenia. Nonadherence to medication has a negative impact on the course of illness for these patients as is shown by data on relapse, rehospitalization, time to remission, and attempted suicide. Several factors that contribute to poor adherence have been identified and need to be taken into account when attempting to address the problem of nonadherence. These risk factors relate to the patient, his or her illness and social situation, and the physician. Among the measures that have the potential to improve adherence to medication are psychosocial interventions, psychoeducation in the form of professional, peer-to-peer or family-to-family interventions, and shared decision making.