Avascular necrosis of bone is a well-described complication of cancer chemotherapy containing corticosteroids and has been observed in lymphomas and acute lymphoblastic leukemia (ALL). This study reports the case of a young male patient in whom avascular necrosis of right femur head was the presenting feature of acute lymphoblastic leukemia. The temporal association in this instance implicates a pathophysiologic relationship between the development of ALL and necrosis.