Bone marrow examination is essentially done to confirm or rule out a hematologic disorder. It also helps in evaluation of non-hematological disorders (e.g. metastasis). Bone marrow may be obtained by aspiration and trephine biopsy. Needles commonly employed for the aspiration of the marrow are Salah needle and Klima needle. Marrow trephine biopsy is performed by one of the trephine biopsy needles like, Jamshidi needle or Westerman-Jensen needle or Islam needle. The biopsy obtained consists of a core of bone with marrow. Trephine biopsy tissue is decalcified and processed like other histopathological tissue containing bone.