Chronic lymphocytic leukemia (CLL) has long been recognized as the most common leukemia in North America, and is characterized by a highly variable clinical course. Some patients never require treatment whereas others require therapy at diagnosis. Prognosis can be predicted by stage at diagnosis, lymphocyte doubling time and biological markers, such as beta2-microglobulin, ZAP-70 or CD38. After a variable period of time, most patients will die from progressive CLL, or the complications of immunosuppression, such as infections and second malignancies. Data for CLL patients in Manitoba is available. However, in India, the interest in this disease is recent, as the population has aged and more cases of CLL are being diagnosed. It is unclear whether the clinical features of CLL are similar in India as in North America and no study has compared the two populations. In this study, we wish to compare the clinical features and outcome of CLL patients who attend the CLL clinic at CancerCare Manitoba against those that attend the All India Institute of Medicine in New Delhi, India. Clinical data will include age and sex of new patients, stage at diagnosis, lymphocyte doubling time and biological prognostic markers. In addition, time to treatment, type of treatment and survival will also be measured. Moreover, we will assess the cause of death in the two populations. These data will provide insight into differences in the characteristics of CLL in Canada and India