Autism spectrum disorder (ASD) is a range of complex neurodevelopment disorders, characterized by social impairments, communication difficulties, and restricted, repetitive, and stereotyped patterns of behavior. Its diagnosis is very difficult and consists of only clinical criteria. The aim of this study is to confirm autism disorder, among three children (2 girls and 1 boy), recruited in a social association of children in a precarious situation, located in Rabat, Morocco, and to evaluate some biological and neurobiological parameters among these children. The confirmation of autistic status is realized using Questionnaire (E2) and the evaluation of biological parameters (organic acids, urinary peptides, toxic metals and essential elements) is done in urine and hair of these children. Obtained children’s scores of E2 Questionnaire, is found in the favor of autism. Moreover, abnormal levels of urinary organic acids, urinary peptides, toxic and essential metals are observed.