Chronic lymphocytic leukemia is one of the most common malignant lymphoid diseases in the western world and is frequently diagnosed by internists. There have been clinically significant changes in method of diagnosis, prognostic tools, supportive care, and treatment over the past 2 decades. Most patients with chronic lymphocytic leukemia now have Rai stage 0 or I disease at diagnosis. Patients with early-stage disease are a heterogeneous group: Approximately 30% to 50% will have accelerated disease progression, and the remainder may live for decades and possibly never require therapy. Recent insights into the biological characteristics of leukemic B cells have led to the discovery of new prognostic tools (immunoglobulin variable-region heavy chain gene mutation status, cytogenetic abnormalities assessed by fluorescent in situ hybridization, and Z-chainâ€“associated protein kinase-70 protein expression) that can identify patients with early-stage disease who are at high risk for early disease progression. These tools allow physicians to individualize counseling, follow-up, and management on the basis of disease risk. In addition, new treatments developed over the past 2 decades (purine nucleoside analogues, monoclonal antibodies, and combination chemoimmunotherapy regimens) have dramatically improved response rates and appear to prolong survival. In this review, the authors discuss the current work-up of lymphocytosis and highlight how to use recently identified prognostic tools to stratify risk in patients with newly diagnosed, early-stage chronic lymphocytic leukemia. Recommendations for patient counseling, follow-up, supportive care, and initial treatment are presented for each risk category.