Despite the advanced age at onset, chronic lymphocytic leukemia (CLL) shortens the life expectancy of the majority of newly diagnosed patients. The management of elderly patients with CLL is more complex than that of younger patients due to the greater frequency of comorbidities and functional impairment as well as reduced organ function. Many of the recent advances in the care of CLL patients (prognostication, more intense combination therapy regimens) are of unclear relevance for elderly patients. This review addresses 5 key questions in the management of elderly patients with CLL: (1) why is classifying the "fitness" of CLL patients necessary; (2) what criteria should be used to classify patient fitness; (3) when should elderly patients be treated; (4) how should therapy be selected for elderly patients; and (5) which therapy is best (for this patient)?