Autism spectrum disorder (ASD) is a neurodevelopmental condition of heterogeneous etiology, categorized by social communication deficits, repetitive or restrictive behaviors and interests. Epidemiological studies display that the incidence of autism is increasing, and the treatment of autism is vitally important. Therefore, the purpose of this article is to reorganize evidence on the effectiveness of vitamins, minerals, essential Fatty Acid, and a Gluten-Free and Casein-Free (GFCF) diet as a treatment for children with ASD. The existing nutrition and dietary therapies have been lectured and their effects on ASD symptoms have been discussed briefly considering specific research. Reviewing the studies showed that nutritional and dietary therapies improved the core symptoms of ASD. This review article investigates the importance of vitamins, minerals, essential fatty acids and GFCF diet and the recent studies suggested that nutrition and dietary supplements may play an active role in improving symptoms of ASD.