Objective: To review the consequences of nonadherence to antipsychotic pharmacotherapy in patients with schizophrenia, as well as associated risk factors for nonadherence and methods of improving adherence. Methods: Review of the literature based on a MEDLINE search on the terms schizophrenia and adherence or compliance, limited to the English language, supplemented by the authors own knowledge of the topic. Results: Nonadherence to antipsychotic therapy is a common reason for relapse and rehospitalization of patients with schizophrenia and thus contributes to the high cost of treating psychoses, adverse events, and lack of insight. Comorbid substance abuse, little family involvement, and a poor clinician-patient relationship are among the risk factors for nonadherence. Patients with a negative attitude towards treatment, which can result from adverse events, are also more likely to be nonadherent. Strategies to improve adherence include optimizing antipsychotic therapy, minimizing adverse events, encouraging patient participation in psychoeducational programs, treating comorbid substance abuse disorders, involving family members in the treatment process, and forging a close therapeutic relationship with the patient. Conclusions: Improving adherence is difficult but necessary for achieving optimal treatment outcomes. Careful selection of drug therapy, with emphasis on a drugs tolerability, combined with nonpharmacologic interventions, may help decrease nonadherence in patients with schizophrenia.