A total of 299 patients with Stage IA-Stage IIB nodal lymphoma treated by irradiation were evaluated for initial reactivation. The abdomen was the major site of reactivation for patients with supradiaphragmatic Hodgkin's disease. The non-Hodgkin's lymphomas reactivated in a variable fashion. Reactivation was prompt for patients with reticulum-cell sarcoma and longer for patients with other lymphomas. Initial extranodal manifestations were present in 24%, 51%, and 63% of patients with Hodgkin's disease, lymphosarcoma, and reticulum-cell sarcoma, respectively.