205 patients with solid cancer, underwent bone marrow biopsy using a Jamshidi needle, regular type. 32 (16%) biopsies were positive for bone marrow metastases. Results were correlated with those of skeletal radioisotope scans, X-ray films and the complaint of bone pain, alone or combined. 27 of 131 (17.5%) patients with positive X-ray film and 31 of 110 patients (28.1%) who complained of bone pain had a positive bone marrow biopsy. 17 of 46 (36.9%) patients with 3 positive parameters had a positive bone marrow biopsy as compared with none of 18 patients whose these 3 parameters were negative. Average values of Hb, WBC, serum alkaline phosphata.se and calcium did not differ between patients with positive or negative bone marrow biopsy. 86 patients were diagnosed to have bone metastases and 35 more patients were diagnosed within a year following the biopsy. Of these 121 patients, 46 of 46 with positive scan, X-ray and pain were diagnosed to have bone metastases as compared to 27 of 30 patients with a positive scan with pain but negative X-ray film. Only 1 of 18 patients with negative parameters was diagnosed as having bone metastases within a year from biopsy. In our experience, it is of no value (unlike in malignant lymphoma and oat cell carcinoma of lung) to obtain a bone marrow biopsy for the detection of bone marrow micrometastases in asymptomatic cancer patients with negative skeletal radioisotope scan and negative bone X-ray films.