The aims of this study are to validate follicular lymphoma international prognostic index (FLIPI) prognostic score and to compare it with the international prognostic index (IPI) in a cohort of 57 Brazilian patients. According to IPI, 24 patients (42%) were in the low-risk, 28 (49%) in the intermediate-risk, and 4 (7%) in the high-risk group. The distribution according to FLIPI was: 20 (35%) in the low-risk, 8 (14%) in the intermediate-risk, and 29 (51%) in the high-risk group. According to IPI score, median OS was not reached for the low-risk, it was 45 months for the intermediate-risk and 25 months for the high-risk group (p < 0.001). When FLIPI score was applied, median OS was not reached for the low and intermediate-risk, and was 42 months for the high-risk group (p = 0.0064). These findings suggest that: (1) FLIPI score could be validated in a Brazilian population; (2) FLIPI is more accurate than IPI to identify FL patients having worse prognosis (51%); (3) IPI seems to be a better tool for clinical decisions because it selected a smaller high-risk group (7%) having worse prognosis. In our opinion, IPI high-risk patients are the real candidates for more aggressive therapies, avoiding unnecessary over-treatment.