A retrospective study of pre-treatment bone marrow biopsies was undertaken to examine the value of bone marrow staging in Hodgkin's Disease. Bone marrow biopsy revealed infiltration in 40 out of 613 cases, (6.5%). These patients were not significantly different from stage 4 patients without marrow involvement with regard to age, sex, anaemia or survival. Peripheral blood lymphopenia and lymphocyte depleted histopathological type were more common in patients with marrow involvement. Bone marrow biopsy altered individual patient management in less than 1% of 613 patients and can no longer be recommended as part of the routine staging in Hodgkin's Disease.