Bone marrow trephine specimens are routinely examined for the histological investigation and diagnosis of lymphoma and other disorders. To achieve this, biopsies are usually fixed in formalin and embedded in paraffin wax for subsequent tinctorial and, often, immunohistochemical staining. However, in this review the authors report the historical developments of immunohistochemical staining on plastic sections, and, in particular, our own developments and updates during the last 20years of using a plastic embedding procedure for the routine reporting of over 50,000 bone marrow trephines. Many evolutionary changes during this period have occurred to provide a simple technique for the successful and excellent demonstration of numerous cellular antigens. While the volume of work and experience relating to immunohistochemistry on plastic-embedded tissue is, the authors we believe, unique, the review also present why the current procedure may revert to use of paraffin wax in the future.