A total of 200 cases of metastatic bone tumors was treated at the Yonsei Medical Center during the 5 years period from January 1976 to December 1980. The results of clinical radiological and pathologic analysis are as followings. 1. Among 200 cases of metastatic bone tumors, common site of cancer comprised the lung (30.5%), breast (15.0%), uterus (8.5%), stomach (6.4%), thyroid (3.5%), liver (3.5%), kidney (3.5%), nasopharynx (3.0%), and prostate (2.0%). In male, common primary sites of cancer were lung, stomach, kidney, oropharynx in decreasing order of incidence and in female, breast, uterus and lung. 2. In metastatic bone tumors, 75.5% were observed in the age group between 41 and 70 year of age, and average age was 53.1 years. 3. The sex distribution was 107 males (53.1%) and 93 females (46.5%). 4. The bones affected most frequently in this series were as followings; In only 9 cases (4.5%), metastasis to bone distal to the elbows and knees occurred. 5. Clinical features in this series were classified according to various conditions. Bone pain noticed on 163 cases (81.5%), fatigue on 152 cases (76.0%) and weight loss on 128 cases (64.0%). 6. Pathologic fractures occurred on 22 cases (11.0%); among them, 13 cases on the femur, 5 cases on the vertebrae, and 1 case on the acetabulum, humerus, rib and clavicle respectively. 7. Hematologically, serum calcium and phosphorus was noticed within normal limits. Serum alkaline phosphatase was slightly elevated and serum acid phosphatase was elevated in all cases of prostatic carcinoma. Serum albumin/ globuline ratio was slightly reversed (3.4/3.5mg%). 8. Radiologically, 86 cases were osteolytic, 10 cases were osteoblastic and 44 cases were mixed type. False negative on X-ray examination with positive finding of scan with 99mTc-MDP were found in 17 cases (27.4%). 9. All cases was treated by various methods; among this series, radiation and chemotherapy performed in 57 cases, radiation in 49 cases, chemotherapy in 14 cases, hormone therapy in 16 cases and radioisotope therapy in 5 cases. For 22 pathologic fractures, conservative treatment was performed in 9 cases, open reduction and internal fixation in 13 cases, open reduction and internal fixation with acrylic cement in 5 cases.