Olanzapine, a serotonin-dopamine receptor antagonist, is one of the novel atypical antipsychotics that is effective against the positive and negative symptoms of schizophrenia with significantly fewer treatment-emergent extrapyramidal symptoms and less akathisia associated with traditional antipsychotics. Compared with traditional agents, olanzapine shows only a few adverse events such as dry mouth, sedation, and increase in appetite. Compared with risperidone, olanzapine causes greater increases in weight gain and body mass index but less hyperprolactinemia. Transient, non-dose-dependent, asymptomatic elevations in liver enzymes have also been noted in olanzapine-treated patients. Because of the comparative efficacy and improved side effect profiles of the atypical antipsychotics, consideration should be given to using the newer agents as preferred treatment for schizophrenia and related psychoses.