Autism is a neurodevelopmental disorder diagnosed clinically on the basis of deficits in social interaction, communication, and range of interests and activities. While, the neurobiologic basis for autism is now established, the specific etiology is unknown. The study tried to put hand on the most offending toxic risk factors for autism through detecting the levels of mercury and lead in the hair of autistic children and whether their levels are correlated with the changes in hair copper and zinc levels. Results showed the lead and mercury were detected in the hair samples of autistic children. The lead levels were significantly increased while mercury levels were significantly decreased in comparison to control group. There were changes in both copper and zinc levels in the hair samples of autistic children as copper levels were significantly higher in autistic cases than in control while, zinc levels were significantly lower in autistic cases than in control. There was positive correlation of Child Autism Rating Scale (CARS) and mercury levels while; Intelligence Quotient (IQ) has significant negative correlation with hair lead levels. By using logistic regression model in the current study, it is found that levels of hair mercury followed by copper then lead were associated with statistically significant increased risk of autism. In conclusion, infantile zinc deficiency and toxic metal accumulation may play principal roles in the pathogenesis of autism.