Abnormalities in control of breathing have been associated with near-miss sudden infant death syndrome. Because caffeine is a respiratory stimulant, its effect on breathing pattern was evaluated in 12 infants with infantile apnea. Caffeine induced a significant increase in ventilation, tidal volume, and mean inspiratory flow. In contrast, no changes were noted in inspiratory time, expiratory time, or total cycle duration. These effects were observed with plasma concentrations of caffeine ranging from 8 to 20 mg/L. Caffeine increases ventilation mainly by increasing central inspiratory drive, and not be effective timing (T1/TTOT). This drug may be of value in near-miss SIDS.