This is a report of a patient who survived a large propranolol overdose, as documented by toxic blood levels. The signs and symptoms were those of profound inotropic and moderate chronotropic cardiotoxicity which failed to respond to parasympatholytics or catecholamines, but subsequently reversed coincident with the administration of glucagon. We report this case because of the sudden development of shock in a patient who looked deceptively well, and because of the improvement apparently brought about by glucagon.