Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder characterized by restricted interests, stereotypical behavior, abnormal communication skills, and impaired social interaction. According to recent epidemiological research, the prevalence of ASD has significantly increased, with 1 in every 36 children now receiving the diagnosis. ASD is monogenic and polygenic. The therapy failure of monogenic targets in heterogeneous ASD has led us to think about polygenic ASD. MicroRNA (miRNA) is short non-coding (20-24 nt) RNA that is involved in the post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of multiple messenger RNAs (mRNAs). Among the RNA interference therapeutics, miRNA therapeutics are used in the clinical phase for many diseases. The literature on the topic includes nucleic acid-based therapy for ASD, but when the articles are reviewed, it becomes clear that these strategies were primarily created for monogenic ASD, which has a single genetic target. In this study, rather than focusing on a single genetic target, where the environment is particularly effective, the complex genetic process in ASD will be organized and used to present the study's findings to the literature. This is done by using a miRNA therapeutic that contains five miRNAs as the active ingredient. The availability of treatment is crucial when taking into account the psychological and economic burden that autism has on society. It is also important to consider the added value effect of therapies on the producer's country. Our research aimed to reverse the phenotype of autism spectrum disorder-like behavior by 10%-30% in juvenile male mice that were prenatally exposed to valproic acid, which is used to model autism spectrum disorder-like behavior. We planned to do this by systemic administration (tail vein injection) using a single viral vector (AAV-PHP.eB-NanoLuciferase-5miRNA) to introduce 5 miRNAs (miR-19a-3p, miR-361-5p, miR-150-5p, miR-126-3p, miR-499a-5p) believed to be associated with ASD into the blood and brain of mice to achieve normal expression levels. At the end of the applications, the recovery of the autism spectrum disorder-like behavior phenotype will be checked with behavioral tests (Open field, New object recognition, Social interaction, Marble burying, Open field, Tail suspension). The level of targeted miRNAs in the brain tissue and blood will be determined by the Real-Time PCR method to check the efficiency of the vector. The distribution of the vector in the brain tissue and the toxicity of the vector in the brain and liver tissue will be determined by the histological / immunofluorescence method. Indirect effects of therapy and candidate coding and non-coding RNAs associated with autism will be determined by RNA sequencing from brain tissue. Additionally, the expression of the genes AEBP2, CDK13, VEGFA, BMPR2, TSC1, and ZBTB18, which are associated with these five miRNAs, will be confirmed by RT-PCR and determined at the protein level by western blot. The viral vector with a backbone that allows polycistronic expression in eukaryotes consists of the neuron-specific promoter Camk2a and the sequence of 5 miRNAs and the PHP.eB serotype with high central nervous system transduction. If this study proves to be successful, new literature understanding will be developed that may enable the development of a novel therapeutic strategy for a variety of neurodevelopmental disorders, including ASD.