Widespread clinical use of the sulfobromophthalein (Bromsulphalein [BSP]) test since its introduction by Rosenthal in 19241 has confirmed the efficacy of this procedure as an index of hepatic parenchymal function. Less commonly appreciated are the hazards associated with the administration of the sulfobromophthalein dye. Of greatest importance is the rare, but frequently fatal, anaphylactoid reaction. This communication will summarize the serious reactions to sulfobromophthalein thus far reported and present the fifth known case of a fatal reaction. This represents the second reported case in which administration of sulfobromophthalein for the first time caused a fatal anaphylactoid reaction. Report of a Case This patient was a 41-year-old woman admitted to Hahnemann Hospital in 1959 with a chief complaint of epigastric and upper abdominal distress. She had noted upper abdominal fulness and bloating for six months, accompanied by eructations, nausea, and occasional vomiting. The symptoms were persistent and aggravated by most