OBJECTIVES: To evaluate effects and resource utilization in outpatients with schizophrenia initiating or changing to monotherapy antipsychotic treatment. METHODS: Data on health effects and resource utilization were collected prospectively in a multicentre observational study with a 12-month duration. There were two cohorts: patients initiating or changing to olanzapine [O] or typical antipsychotic monotherapy [T]. The cumulative numbers of inpatient days, days in day-hospital/day-care and outpatient consultations were calculated per patient and per user separately. Treatment groups were compared in terms of these variables using adjusted analysis. The comparison in terms of response, relapse, worsening and minimally symptomatic patients was made using logistic regression analysis with adjustment for baseline variables. RESULTS: A total of 344 patients were included: 254 in [O] and 90 in [T]. The baseline characteristics were comparable for both groups. Clinical response was achieved in 53.7% and 27.5% patients in [O] and [T] respectively; OR vs. olanzapine 0.36 (p=0.001). No significant differences were detected between groups in terms of relapses and worsened CGI score. There were more minimally symptomatic patients in [O] (34.3%) than in [T] (19.2%). The mean number of inpatient days was 4.96 and 6.77 per patient; and 45.85 and 46.67 per user in [O] and [T] respectively. The mean number of days in day-hospital/day-care per patient was 4.43, 9.3 per patient, and 57.00 and 99.17 per user in [O] and [T] respectively. The mean number of consultations was 8.00 in [O] and 7.5 [T]. Significantly more patients remained on initial drug in [O] (67.9%) than in [T] (50.7%); OR vs olanzapine 0.48; p=0.00113. CONCLUSIONS: This preliminary analysis show that in group [O] in comparison to [T] a greater proportion of patients achieved clinical response and remained on initial drug. The health care resource utilization seems to be lower both per patient and user in [O].