Chronic lymphocytic leukemia (CLL) is the most common leukemia in the United States. In 1-10% of cases, it can undergo Richter's transformation (RT) to either diffuse large B cell lymphoma (DLBCL) or Hodgkin's lymphoma (HL). Diagnosis requires histologic confirmation by tissue biopsy. PET/CT has been studied to in several series to look at its predictive value for identifying RT in biopsies. in this review, we will discuss the role of PET/CT to identify RT in patients CLL and its utility in clinical practice.