Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of matureâappearing lymphocytes in blood, bone marrow, lymph nodes, and spleen with a median lymphocyte count of 20–30 × 109/L at the time of diagnosis. In half of the patients, the lymphocyte count doubles over a period of 1âyear and cyclic rise up to 50 × 109/L can occur in untreated patients while in others the count may remain stable for years. Based on the cytogenetic and molecular studies, it has been demonstrated that multiple clones may occur in CLL and clonal evolution is a frequent occurrence. The transformation of CLL to a highâgrade nonâHodgkin’s lymphoma such as diffuse large B cell lymphoma, Hodgkin lymphoma, and prolymphocytic leukemia is well documented. Whereas the transformation of CLL to acute leukemia occurs in <1% cases and this contrasts the almost invariable progression in patients with chronic myeloid leukemia. Here, we report a rare case of a 55âyearâold lady, a diagnosed case of CLL transforming into Bâcell acute lymphocytic leukemia over a very short interval of 1 week period.