To detect and describe the incidence of musculoskeletal manifestations in different malignant diseases as well as their relation to the treatment received whether by chemotherapy or radiation therapy. Sixty patients with different malignant diseases were included in this study, 45 with solid tumors and 15 patients with hematological malignancy. The mean age was 46.55 +/- 11.04 years and the mean disease duration was 2 +/- 0.75 years. The patients were fully examined for any rheumatologic involvement, laboratory investigations were performed as well as dual energy X-ray absorptiometry study for bone densitometry. Treatment strategies were assessed including the chemotherapeutics, radiation therapy, and/or surgery. Myalgias and arthralgias were the most frequent followed by flexor tenosynovitis, frozen shoulder, and fibromyalgia syndrome. Hypertrophic osteoarthropathy was seen in five patients, cutaneous vasculitis in two patients as well as arthritis. Osteonecrosis was present in one of the lunate carpal bones of a patient with non-Hodgkin's lymphoma (1.67%) and receiving high dose steroids. Rheumatoid factor was positive in four patients, three of which had hepatitis C virus positivity and cryoglobulins. Anti-neutrophil cytoplasmic antibody was negative in all the studied patients. The bone mineral density was significantly reduced in the patients with malignancy compared to the control. Mild to moderate osteoporosis was present, being more evident in the spine and forearm. The bone loss was higher in those with solid tumors and even more obvious in those receiving aromatase inhibitors. Musculoskeletal manifestations occurring during malignancies and following the treatment represent a significant percentage of symptoms and signs which may raise a clue to differential diagnosis.