Introduction: Chronic lymphocytic leukemia (CLL) is a neoplastic disease characterized by the accumulation of small mature appearing lymphocytes in the blood, marrow, and lymphoid tissues. Fludarabine and cyclophosphamide is a highly active and well-tolerated regimen with an acceptable level of toxicity in patients with previously untreated CLLAim of the work: This study aimed at better definition and characterization of our newly diagnosed CLL patients regarding their clinical presentation, staging and evaluating the efficacy, response rate, factors affecting response, and toxicity of fludarabine and cyclophosphamide as a first-line treatment.Materials and methods: Between January 2002 and December 2006, 31 adult patients presented to the medical oncology department, National Cancer Institute with previously untreated chronic lymphocytic leukemia treated with FC regimen were included in this study. Clinical and laboratory findings of these patients were assessed. Also response and toxicity to FC regimens and diseases-free and overall survivals were assessed. Results: Complete clinical remission was achieved in 48.4% of patients, the overall response rate (ORR) was 64.5%, the mean overall survival was 35.4 months, and the median time to disease progression was 25 months. Conclusion: This study indicates that the combination of fludarabine and cyclophosphamide is able to induce a high response rate with acceptable toxicity in newly diagnosed CLL patients