The Follicular Lymphoma International Prognostic Index (FLIPI) was developed to predict prognosis of patients with follicular lymphoma (FL). However, it was based on different protocols, none of which included rituximab. The current analysis aimed at evaluating the predictive value of the FLIPI for treatment outcome in 362 patients with advanced-stage FL treated front-line with rituximab/CHOP in a prospective trial of the German Low Grade Lymphoma Study Group. According to the FLIPI, 14% of the patients were classified as low-risk, 41% as intermediate-risk, and 45% as high-risk patients. With a 2-year time to treatment failure (TTF) of 67%, high-risk patients had a significantly shorter TTF as compared with low- or intermediate-risk patients (2-year TTF of 92% and 90%, respectively; P < .001). Our data demonstrate that the FLIPI is able to identify high-risk patients with advanced-stage FL after first-line treatment with rituximab/chemotherapy.