Sclerosing peritonitis developed in a 43-year-old man with angina pectoris who had been receiving the beta-adrenergic receptor antagonist, propranolol. The patient had abdominal and back pain, weight loss, a midabdominal fullness, ascites, and evidence of partial small bowel obstruction. At surgery, the small bowel was distended and encased by dense fibrous tissue. Infectious and neoplastic causes of fibrosing peritoneal inflammation were excluded. The patient described in this report illustrates several features commonly experienced by individuals who developed sclerosing peritonitis associated with beta-adrenergic receptor blockade therapy. To my knowledge, the development of ascites and considerable ascitic fluid leukocytosis have not been described previously with this disorder.