Several cases have been reported, in which a rather large dose of streptomycin given intraperitoneally at operation has produced respiratory paralysis. In these cases the treatment has usually consisted of respirator ventilation and administration of atropine and neostigmine. In animal experiments, in which a cessation of breathing has been produced, calcium salts have produced quick recovery. The authors present a case, in which appendicetomy was performed on a 10-year-old girl for a perforated appendix at the end of which, an overdose of intraperitoneal streptomycin was given, followed 10 minutes later by complete cessation of breathing. The patient had to be intubated again and put into a respirator. Neostigmine and atropine were used without noticeable effect. One and a half hours after the breathing had stopped 0.6 g calcium chloride was given intravenously and the girl recovered immediately and completely.