Intraoperative anaphylaxis secondary to exposure to latex is a serious and potentially life-threatening phenomenon that has been recognized more frequently in recent years. Between 1989 and 1992, twenty-one patients had a Type-I (anaphylactic) reaction to latex intraoperatively at The Children's Hospital of Philadelphia. Twelve (57 per cent) of these patients had spina bifida. Six patients (29 per cent) had cerebral palsy, and five of them had a ventriculoperitoneal shunt. Of the remaining three patients, one (5 per cent) had exstrophy of the bladder, one had VATER syndrome, and one had Duchenne muscular dystrophy. All of the patients had had at least two previous operative procedures. Overall, sixteen patients (76 per cent) had a ventriculoperitoneal shunt. The manifestations of the allergic reaction included a rash in fifteen patients (71 per cent), hypotension in fifteen, tachycardia in eleven (52 per cent), bronchospasm in ten (48 per cent), bradycardia in two (10 per ent), and cardiac arrest in two. The symptoms occurred within minutes after the induction of the anesthesia in all but one patient, in whom hypotension and cardiovascular arrest developed approximately one hour after the beginning of the operation. Two patients had a full cardiopulmonary arrest while under the anesthesia. All twenty-one patients responded to management; there were no deaths. Of the six patients who had cerebral palsy, five had been managed with a ventriculoperitoneal shunt because of hydrocephalus following a previous intraventricular hemorrhage that was related to prematurity.(ABSTRACT TRUNCATED AT 250 WORDS)