Primary prostatic lymphoma is a rare disease. We report a 73-year-old man who initially presented with features of bladder outflow obstruction. Histology revealed non-Hodgkin's lymphoma. He was treated with radical radiotherapy with complete regression of disease. Although the follow-up period is, as yet, relatively short, the apparently good result in this patient supports the view of other recent reports that the outcome in this situation depends on the features of the individual disease rather than it being universally poor as had been previously suggested.