Objective: this study assessed treatment outcomes of Latin American patients with bipolar I disorder (manic or mixed episodes) who included olanzapine in their treatment regimen compared with patients who did not. Materials and methods: patients from seven Latin American countries participated in this prospective, observational, noninterventional, open-label study conducted over 12 months. Main outcome measures were: (i) time to remission of manic symptoms (Young Mania Rating Scale (YMRS) ≤ 12), (ii) time to hospitalisation after remission, and (iii) time to relapse with a manic (YMRS ≥ 15) or depressive (Montgomery-Åsberg Depression Rating Scale (MADRS) ≥ 15) episode. Comparisons of clinical outcomes only included data from visits where patients continued to use their baseline treatment. Results: at baseline, 516 patients included olanzapine in their treatment and 246 did not; 67.5% of all patients had a manic episode and 31.9% had a mixed episode. Time to remission of manic symptoms was similar between groups (log-rank P-value = 0.133). Time to hospitalisation (log-rank P-value < 0.0001) and relapse with a manic (log-rank P value = 0.0002), but not a depressive (log-rank P-value = 0.363) episode was significantly longer in the olanzapine group compared with the non-olanzapine group. Similar rates of treatment-emergent adverse events and statistically significant improvements in quality of life (12-Item Short Form Health Survey) were observed in both groups. Conclusions: inclusion of olanzapine in bipolar I disorder therapy may allow patients from Latin America to maintain clinically effective and long-term responses to treatment. ©INNN, 2009.