We studied the early infectious complications of all children admitted for intensive care over a six-year period who were at high risk of having severe aspiration of gastric or pharyngeal secretions. Patients were only analyzed if they required mechanical ventilation for acute respiratory failure, had a blood culture obtained in the first 48 hours, and survived at least 24 hours. Infections were identified by positive blood cultures. possible infections were defined as fever (over 38.5-degrees-C), abnormal leukocyte count (>10,000 or <5000), and a potential pathogen in tracheal secretions. Patients' diagnoses included near-drowning (13), aspirated foreign body (5), observed aspiration of gastric contents in a hospitalized patient (2), and hydrocarbon aspiration (1). Of 21 high-risk patients, five (23.8%) had infections and two (9.5%) had possible infections in the first 48 hours. In contrast, no late infections were seen. Infected patients tended to be older (P < 0.05). No diagnostic features in the first two days of hospitalization reliably identified those who would develop early infections (P > 0.05). Since early life-threatening infection is common and cannot be reliably predicted by clinical signs, we recommend aggressive bacteriologic surveillance and the administration of IV antibiotics on admission to all patients in respiratory failure requiring mechanical ventilation after presumed aspiration of gastric or pharyngeal secretions.