We present our experience with a patient with effusive pericarditis and recurrent pleural effusion that first developed 23 yr after radiation treatment for the nodular sclerosis type of Hodgkin's disease. Extensive diagnostic work up including pericardial and pleural biopsy, excluded any other cause (than radiation) of the recurrent pleural effusion. Pericarditis and pleural effusion were not controlled with regimens including steroid and non-steroid anti-inflammatory agents. The fluid collections improved only with per os doxycycline (100 mg twice a day). Four episodes of recurrent pleural effusions were also controlled with per os doxycycline. Although the concentration of doxycycline in the pericardial and pleural fluid when given orally is smaller compared with that achieved by direct installation of the agent, the fact that all episodes of pleural effusion improved with an agent commonly used for pleurodesis is intriguing.