Caffeine is commonly used to treat apnea in newborn infants, but the long‐term consequences of this treatment are poorly understood. We previously showed that neonatal caffeine treatment induces long lasting changes on respiratory control in adult male rats but not in females. To test the interaction of neonatal caffeine treatment and sexual hormone on respiratory pattern, adult male and female rats, that received by gavage either caffeine (15mg/kg/day – postnatal days 3–12) or water (control) were sham‐operated or gonadectomized. After 14 days of recovery, ventilatory parameters were measured under normoxia and in response to moderate hypoxia (12% O2 – 20 min). In sham males, a significant interaction (treatment x hypoxia) was obtained for the increase in respiratory frequency (p<0.001) and the decrease in inspiratory time (p<0.01) in hypoxia. No interaction was obtained in gonadectomized rats. In females, no interaction between hypoxia and nicotine was observed in sham or ovarectomized rats. This suggests that endogenous circulating testosterone in adult males is necessary to reveal the alterations induced by caffeine on respiratory control. Supported by CIHR.