Autism spectrum disorder is a neurodevelopmental disorder with a strong genetic basis. This study has been conducted to determine prevelance and the possible risk factors of autism. . This studty is a retrospective study that included101 children (67 males and 34 female). Their ages ranged from 26 years with mean age 3.87±1.03 (26) . Cases was collected from KGs, special centers and psychiatry clinic, Pediatric Department , Benha univeristiy hospital and Benha specialized Hospital . The included child was subjected to: the followings tools: Confirmation of diagnosis using DSMV criteria,, and assessment of severity of autistic symptoms using childhood autism rating scale (CARS). A small structured questionnaire and complete medical history stressing on developmental, therapeutic and behavioral histories were also developed and administered . ASD prevalence was 1 in51 childrenThe current study was conducted on 101 autistic children, their ages range from2 – 6 years with a mean value of 3.87±1.03 years, 66.3 of autistic children were males and 33.7 were females, with a male/female ratio of 2:1; (p > 0.05 all).Advanced paternal age (father, P35 years) at birth was found in 91% of cases and the difference was statistically significant. Positive family history was found to be statistically unsignificant. As regards natal factors, a history of low birth weight, delivery by ceserian section were significantly higher among cases . Also postnatal factors as history of hypoxia, resuscitation and history of jaundice were considered significantly risk factors for autism(p=0.000).