A multicentre single-arm study testing the efficacy and toxicity of the oral combination of fludarabine and cyclophosphamide (FC) over 5 d in 75 patients with untreated B cell-chronic lymphocytic leukaemia. Oral FC demonstrated high efficacy with overall (OR) and complete response (CR) rates of 80% and 53%, respectively. Out of the 30 CR patients studied for Minimal Residual Disease (MRD) using 4-colour flow-cytometry and the 22 using Clonospecific polymerase chain reaction, 22 (66%) and 16 (68%), respectively, were MRD negative. Median survival and median treatment-free interval had not been reached at 7 years of follow-up. Median progression-free survival (PFS) was 5 years. Toxicity was acceptable, with 52% and 16% of National Cancer Institute grade 3/4 neutropenia and infections, respectively. Gastrointestinal toxicity was mild. Oral FC demonstrated a high efficacy and an acceptable safety profile and may be considered as the standard first line treatment in chronic lymphocytic leukaemia.