A 64-year-old woman with mixed cellularity Hodgkin's disease diagnosed in 1972 developed a malignant lymphoma of the conjunctiva 14 years later. She had undergone combined chemotherapy and radiation therapy for Hodgkin's disease. Non-Hodgkin's lymphomas developing after Hodgkin's disease have been reported with increasing frequency in recent years. It is important to recognise a separate malignant lymphoma in a patient with Hodgkin's disease because of the different treatment offered for each of these diseases.