The objective of this study was to compare in-patient drug use patterns, costs, and outcomes associated with risperidone or olanzapine in a naturalistic clinical setting. Retrospective chart reviews of 92 patients with psychotic disorders were conducted at the University of Malaya Medical Centre (UMMC). Data was collected from patients who were hospitalized and for whom risperidone or olanzapine was the drug of first choice for long-term pharmacologic treatment. Proportion of patients for whom efficacy of the studied treatment could be established (as rated by the treating physician) was higher, but not significantly, with risperidone compared to olanzapine (p = 0.46). The average dose of the studied medication was 2.9 ± 1.0 mg/day for risperidone and 9.7 ± 2.4 mg/day for olanzapine. The total cost was significantly higher (p