Ten preterm infants intubated 4-19 days for treatment of respiratory distress syndrome were given a cool racemic epinephrine aerosol after extubation to determine whether it had a beneficial effect on pulmonary function. Before and after the aerosol, tidal volume (VT), peak inspiratory flowrate (PIFR), peak expiratory flowrate, arterial blood gases, and vital signs were measured during quiet breathing. The temperature of inspired gas, with the micronebulizer in the incubator, decreased to 19-22°C by the end of the aerosol treatment. Two infants developed apnea during aerosol therapy, and the respiratory rate was significantly decreased (P<0.01) after the aerosol. VT and PIFR increased significantly (P < 0.05) after the aerosol, but there was no significant difference (P > 0.10) in arterial blood gas values or minute ventilation after the aerosol. Because of potential complications of aerosol therapy, we suggest that cool racemic epinephrine aerosols not be administered routinely to neonates after extubation. (Marshall TA, Pai S. The Effects of Racemic Epinephrine Aerosol Therapy after Prolonged Intubation in Preterm Infants. Respir Care 1984;29:138-143.