The aim of the study was to determine the safety and efficacy of the combination of fludarabine (FLU), cyclophosphamide (CY) and mitoxantrone (FLU/CY/MITO) in untreated follicular lymphomas (FL), Sixty patients with newly diagnosed stage II bulky to IV FL, median age 59 years (range 36-70), received FLU/CY/MITO regimen (FLU 25 mg/m2 days 1-3, CY 300 mg/m2 days 1-3, Mito 10 mg/m2 day 1). Patients received antibiotic oral prophylaxis during all treatments, and growth factors (G-CSF) when grade III granulocytopenia (WHO) occurred. The overall response rate was 87%: 46 patients achieved complete response (CR) (77%), 6 a partial response (10%) and 8 were non-responders. Fifty patients are surviving with a median observation time of 31 months. The 4-year estimated probability of overall survival and failure-free survival were 78.2% and 45% respectively. Thirty-five patients (58%) are still in CR. Sixty percent of patients experienced grade III-IV granulocytopenia. Two patients suffered grade III pulmonary infection and one grade III liver toxicity. In a subset of 46 patients, bcl-2 translocation was positive in bone marrow (BM) and/or peripheral blood (PB) of 36 patients. At the end of treatment, 25 of these patients had CR and 19 (76%) converted to polymerase chain reaction (PCR) negativity. FLU/CY/MITO regimen showed a high level of activity in follicular lymphoma. Toxicity, mainly hematological, was acceptable and the treatment was made feasible by the use of antibiotic prophylaxis and G-CSF. Significant non-hematological toxicities were seen, but no patients died. The conversion of bcl-2 from positive to negative by PCR in BM and/or PB suggests a possible role for this treatment in clearing minimal residual disease and improving patients' outcome.