Thirteen of 356 children consecutively admitted for treatment of status asthmaticus in a 37-month period experienced 19 episodes of respiratory failure, an incidence of 5.3%. In this retrospective study, all children received similar pharmacologic therapy after admission, and all were treated with nasotracheal intubation and controlled ventilation with a volume-cycled ventilator. Mean duration of mechanical ventilation was 54 hours and mean duration of hospital stay was 7.5 days. Complications occurred in nine of 19 episodes and there was one death not directly related to acute asthma. It is possible that 12 of the 19 episodes of respiratory failure might have been prevented by more prompt or more appropriate treatment of the child with acute asthma.