Autism is a neurological disorder characterized by qualitative impairments in social interaction, qualitative impairments in communication, and restricted repetitive, stereotyped patterns of behavior, interests, and activities. Autistic Spectrum Disorders (ASDs) are relatively common without known etiology can be found in 80-90% of cases. The study aimed to evaluate the effect of a parent-focused intervention for autistic children on parenting stress at Assiut City. Subjects and methods: The study was Quasi-experimental research design. It was conducted in all autism centers at Assiut city which includes 7 centers and included 73 parents who agreed to participate in this study selected by convenient sample; this sample included 47 mothers and 26 fathers. The study included three tools: - a structured interview sheet, parents' knowledge assessment about autism, and parenting stress scale. The main results of the study indicated that there was highly statistically significant differences between mothers' and fathers' knowledge about autism (P-value = 0.000) in pre, immediate post-test and follow-up. Moreover there was highly statistically significant difference between Parental stress scale for mothers and fathers in pre-test and immediate post-test respectively (P-value= 0.000 *& 0.002*) while no statistically significant difference between pre-test and follow-up respectively (P-value= 0.152 & 0.417). The study Concluded that there was improvement of parents' knowledge about autism in immediate post-test and follow up; moreover the parents' stress level was decreased in immediate post-test than pre-test while the stress level again slightly increase during follow up test. The study recommended that: Nursing staff should play a much greater role in supporting parents and providing them with important information through pediatrics clinics, Maternal and Child Health Centers (MCH), and others.