The hospital records of 895 patients presenting to this centre with a diagnosis of Hodgkin's or non-Hodgkin's lymphoma have been reviewed. In the records of 26 patients there was evidence for or against the occurrence of abscopal regression with radiotherapy. Attention is drawn to inevitable inaccuracy in a retrospective study of this type. Evidence of abscopal regression was seen in the records of 10 patients, four with Hodgkin's and six with non-Hodgkin's lymphoma. It appears to be associated with a more favourable prognosis in patients with non-Hodgkin's lymphoma. It is suggested that this phenomenon is elicitable in more patients than is commonly recognised, and that together with response to low dose total body irradiation, could be explained by radiation damage to normal lymphocytes.