For almost 10 years imatinib has been the therapeutic standard of chronic myeloid leukemia. The introduction of other tyrosine kinase inhibitors (TKIs) raised a debate on treatment optimization. The debate is still heated: some studies have protocol restrictions or limited follow-up; in other studies, some relevant data are missing. The aim of this report is to provide a comprehensive, long-term, intention-to-treat, analysis of 559 newly diagnosed, chronic-phase, patients treated frontline with imatinib. With a minimum follow-up of 66 months, 65% of patients were still on imatinib, 19% were on alternative treatment, 12% died and 4% were lost to follow-up. The prognostic value of BCR-ABL1 ratio at 3 months (⩽10% in 81% of patients) was confirmed. The prognostic value of complete cytogenetic response and major molecular response at 1 year was confirmed. The 6-year overall survival was 89%, but as 50% of deaths occurred in remission, the 6-year cumulative incidence of leukemia-related death was 5%. The long-term outcome of first-line imatinib was excellent, also because of second-line treatment with other TKIs, but all responses and outcomes were inferior in high-risk patients, suggesting that to optimize treatment results, a specific risk-adapted treatment is needed for such patients.