The association of lymphoid neoplasms with Hodgkin's disease is being recognized with increasing frequency. These tumors often occur concurrently with Hodgkin's disease and are not as clearly related to therapy as are other secondary tumors. Presumably, the immune deficiency state found in Hodgkin's disease plays an important role. A patient with Hodgkin's disease and simultaneous acute lymphocytic leukemia is reported. The leukemia was B cell in type, a rare form that most likely is identical to acute lymphosarcoma cell leukemia of immature cell type. This case expands the spectrum of lymphoid neoplasms known to occur with Hodgkin's disease. The fact that the leukemia responded to therapy for Hogkin's disease suggests that some lymphoproliferative disorders discovered subsequent to therapy are not the result of therapy but recurrences of previously undetected and therapeutically suppressed disease.