During an hospitalization, a ten-day-old newborn infant was treated with ceftriaxone (Rocephine i.v., 390 mg/day) for an infection secondary to the presence of an umbilical catheter. A few minutes after the end of the fifth injection, the infant presented with cyanosis, initially localized at the perfusion site, then generalized, a tachycardia followed by acute circulatory failure with arterial hypotension and finally a multiple organe failure with coagulation, kidney and liver dysfunction. The infant received classical resuscitation treatment and recovered without short term sequelae. The time of onset was in favour of drug-induced accident. A postnatal sensitization during previous injections might have occurred, although the latency of immediate hypersensitivity reactions after a first sensitizing contact is usually longer. A sensitization in utero or via breast feeding was ruled out due to the absence of maternal exposure to ceftriaxone. The absence of urticaria and bronchospasm, and the initial localization of cyanosis were not in favour of a classic allergic disease. An other cause, toxic or infectious cannot be ruled out.