Recent advances in the treatment of hematologic malignancies have been paralleled by renewed interest on the part of pathologists and hematologists in methods of obtaining and preparing bone marrow for diagnostic studies. A thorough bone marrow morphologic involves examination of peripheral blood smears, direct, particle, and buffy coat bone marrow smears, trephine biopsy imprints, particle and trephine biopsy sections, and marrow volumetric data. The information obtained from the study of these various specimens is complementary. Frequently it is a combination of clues gathered from examination of several different preparations that leads to a correct diagnosis. Utilization of biopsy material by the methods described provides complete, accurate and reproducible information and minimizes the necessity for repeating a biopsy for morphologic diagnosis or ancillary studies.