Background: Chronic lymphoproliferative disorders include a variety of diseases which are often a diagnostic problem for clinical hematologists. Aim: To study prospectively the distribution and incidence of chronic lymphoproliferative disorders in Chile and compare them with those of other Western, Latin American and Oriental countries. Patients and methods: A group of 132 patients were studied in a 36 months period (1999-2001), with a panel of monoclonal antibodies. A score for chronic lymphocytic leukemia was employed to differentiate it from other B-cell disorders. Results: The median age was 63 years old (range 32-94). Most patients had B-cell tumors (109) and the rest (23), T-cell tumors (82% vs 18%). Forty five percent of patients with B-cell tumors had a chronic lymphocytic leukemia (CLL), while the others were disseminated lymphomas. The incidence of T-cell tumors was slightly higher than that of other Western countries. Noteworthy is that the most common of these disorders was adult T cell leukemia/lymphoma (ATLL), in concordance with the high HTLV-1 seroprevalence in Chile. Conclusions: A morphologic, immunophenotypic and pathological study in a large number of patients with chronic lymphoproliferative disorders in Chile, shows a relatively low incidence of CLL when compared to other chronic B-cell tumors and a high representation of ATLL associated to HTLV-1 infection, compared with other Western countries. The lower incidence of CLL in our study might be due to patient's selection and/or underdiagnosis of this disease as a substantial proportion of CLL are asymptomatic (Rev Méd Chile 2003; 131: 291-8).