The present essay aims to study apnea in neonates, its pathophysiology, predisposing factors, diagnosis and treatment.Apnea has been defined most widely as cessation of breathing in excess of 15 seconds duration ,typically accompanied by desaturation and bradycardia.Apnea is a clinical syndrome that may be attributed to a variety of underlined disorders as prematurity, sepsis, GIT disorders ,neurological disorders, metabolic disorders, temperature instability, maternal drugs and cardiac anomalies.Apnea in infants may be classified as one of three types:1- Central apnea is complete cessation of breathing.2- Obstructive apnea referred to an absence of nasal airflow despite respiratory efforts.3- Mixed apnea.Apnea occurs in approximately 25% of preterm infants during the first 10 days of life to those weigh less than 1.8 kg or less than34 weeks gestational age.