Important steps in bone marrow aspirate evaluation include determining if bone marrow evaluation is indicated; using appropriate aspirate collection, smear preparation, and staining techniques; and performing a systematic approach for the cytologic evaluation. The cytologic evaluation of bone marrow requires knowledge of the morphology of bone marrow cell types, the proportion of these cell types normally present, and the ability to evaluate overall cellularity of bone marrow. Accurate interpretation of bone marrow cytologic findings depends on evaluation of a current complete blood cell count. These components are the pillars of getting the most useful information in the diagnosis of hematologic disorders.