Our aim is to to assess the effect of the early intensive behavioral intervention (EIBI) on the severity of symptoms in children with autism spectrum disorder. A quasiexipermintal design utilized with a sample of (28) children diagnosed with ASD by a consultant psychiatrist. Data collected using four tools, one for assessing sociodemographic, clinical and developmental chrachterstics of children, the Mini International Neuropsychiatric Interview (MINI-KID) for assessing psychiatric comorbidity, Gilliam Autism Rating Scale (GARS) for assessing the severity of autistic symptoms and Vinland Adaptive Behavior Scale (VABS) for assessing adaptive behavio. Results revealed modification in the symptoms included domains of communication, social interaction and stereotyped behavior respectively. Generally, Effect of the intervention is large and significant in all domains of autism severity scores and adaptive behavior scores. Results also showed that intervention is more effective in the second six months than first six months. Therefore, it is recommended for nurses to enhance adequate training about adaptive behavior for those children to minimize their dependence and disability through integration of EIBI as one of the effective intervention to children with autism.