Schizophrenia is a serious and disabling psychiatric disorder affecting approximately 1% of the world's population, with its economic cost in the United States alone estimated to exceed that of all cancers combined. The new generation of atypical antipsychotics introduced over the past decade have comparable or greater efficacy than traditional antipsychotics in treating the psychotic symptoms of schizophrenia and a much improved neurologic side effect profile. Quetiapine, the fourth atypical antipsychotic marketed in the United States, was approved by the U.S. Food and Drug Administration in September 1997 and is also currently approved in over 70 countries worldwide for the treatment of psychosis associated with schizophrenia. This article will review the clinical trials examining the efficacy, safety, and tolerability of quetiapine in the treatment of patients with schizophrenia.