A 6-year experience with bone marrow aspirates and biopsies (96 cases) positive for metastatic carcinoma is reviewed. Marrow examination detected secondary carcinoma in 58 cases (60%) despite negative roentgenographic and/or bone scan examinations. Breast carcinoma was the most frequent primary site. The bone marrow biopsy was superior to the aspirate in finding carcinoma (97% vs. 72%). However, in an occasional case, tumor was found only in aspirate preparations. Both procedures should be considered complementary and are recommended in the marrow evaluation of patients with carcinoma.