Chylothorax is caused by disruption or obstruction of the thoracic duct or its tributaries that results in the leakage of chyle into the pleural space. A number of interventions have been used to treat chylothorax including the treatment of the underlying disease. Lymphoma is found in 70% of cases with nontraumatic malignant aetiology. Although patients usually have advanced lymphoma, supradiaphragmatic disease is not always present. We discuss the case of a 63-year-old woman presenting with progressive respiratory symptoms due to chylothorax. She was diagnosed with a stage IIE retroperitoneal grade 1 follicular lymphoma extending from the coeliac trunk towards the pelvic inlet. Despite thoracocentesis and medium-chain triglycerides (MCT), diet chylothorax reoccurred. After low dose radiotherapy (2 × 2 Gy) to the abdominal lymphoma there was a marked decrease in lymphadenopathy at the coeliac trunk and a complete regression of the pleural fluid. In this case, radiotherapy was shown to be an effective nontoxic treatment option for lymphoma-associated chylothorax with long-term remission of pleural effusion.