We report on a case of an osteolytic lesion of the femur in a patient with previous prostate cancer, affected by hip osteoarthritis. Computed tomography of the femur demonstrated the presence of fat in the lesion. Computed tomography-guided fine needle aspiration biopsy revealed mature adipose tissue along with hematopoietic precursor cells. Surgical management consisted of curettage and packing with allograft, followed later by total hip arthroplasty. This is the third case of intraosseous myelolipoma reported in the literature.