Nodular regenerative hyperplasia of the liver, an uncommonly reported and poorly defined clinicopathological entity, obscured clinical diagnosis and was misdiagnosed on hepatic biopsy in a recent case. Approximately 19 cases are recorded in the English literature. Six patients had Felty's syndrome, about 12 patients had congestive heart failure, and the patient under discussion had subacute bacterial endocarditis. Light- and electron-microscopic examination was utilized to define nodular regenerative hyperplasia pathologically. Features common to all reported cases are discussed but elucidation of the pathogenesis of nodular regenerative hyperplasia must await further investigation.