The risk of second malignancies after successful treatment for Hodgkin disease can be considerable. The most common malignancies are solid tumors arising in irradiated sites, such as the breast and thyroid gland after mantle field radiation. Sarcomas and other musculoskeletal tumors are also seen. We describe a young woman who developed an intra-abdominal desmoid tumor more than 4 years after completing therapy for Stage IIB Hodgkin disease, treated with combination chemotherapy (ABVD) and mantle irradiation. The tumor did not occur at either a surgical site or within a radiation field. She did not carry a mutation for familial adenomatosis polypoli.