We review our cases of leukemia and lymphoma relapse after allogeneic marrow transplant and describe here a series of 10 patients with extramedullary (EM) relapse. In the 13 relapses in acute myeloid leukemia, 5 cases had EM involvement. There were 3 EM involvement out of 13 acute lymphoblastic leukemia relapses, one EM disease in 11 chronic myeloid leukemia relapses and one case of lymphoma with EM relapse. A common observation is that in some of these cases, EM relapse occurred in the presence of continuous marrow remission, In those cases with both marrow and EM involvement marrow remission could often be achieved and maintained temporarily while EM disease progressed despite chemotherapy or immunotherapeutic measures such as immunosuppressant withdrawal and donor lymphocyte infusion. Survival in partial remission after relapse could be prolonged in some cases but eventual death from progressive disease was often the case.