Elective cesarean section has been increased in the last years and this leadto very important question. When is the best time for termination of pregnancywithout respiratory morbidity in the neonates?Cesarean section is an evident risk factor for neonatal respiratorymorbidity lack of hormones associated with labor could explain this association.Most obstetricians are generally unaware of the consequences of theiractions because they don't manage the care of neonates.Our aim in this study is to determine the most proper time for electivecesarean section with the least incidence of respiratory morbidity by comparisonbetween respiratory out come of neonates at 38 wks versus 39 weeks.The study were conducted on 200 healthy pregnant women who deliveredby Elective cesarean section in Kasr El Eini hospital in a period from December2010 to July 2011.All of mothers were subjected to full detailed history, examination and U/S.All neonates collected in the 1st day of their life and subjected too fulldetailed history, examinations, lab investigations, chest X-ray and chest sonar.