Bone marrow examination is an important procedure in diagnosis of various hematological and non hematological disorders. The chapter gives indications of doing bone marrow aspiration as well as bone marrow biopsy. It also gives the procedure for doing bone marrow aspiration and biopsy. It gives detailed methodology for processing bone marrow biopsy along with staining procedure applicable to bone marrow biopsy. Immunohistochemistry is an important technique which has been touched upon in the chapter pertaining to bone marrow biopsy. A simplified protocol has been given. Special sample handling requirements for various hematological tests have been mentioned in the form of a table.