Background: Autism is a neurodevelopmental disorder which interferes with the person's ability to communicate and relate to others. Median of global prevalence of autism spectrum disorders is 62/10 000. Both genetic and environmental factors are responsible for its development. The aim of this study was to investigate the sociodemographic, prenatal, perinatal, and neonatal risk factors of autism. Methods: This study was done from the digital database of the child guidance clinic of the department of Psychiatry of a tertiary care hospital in Kolkata. Results: In this study male-female ratio among autistic children was found 3:1. Two thirds of the children came from urban nuclear families. Families of autistic children were more or less evenly distributed among all social classes. Antenatal, Perinatal and neonatal factors which were found to be significantly associated with Autism were antepartum haemorrhage or threatened abortion, pregnancy induced hypertension, prematurity and pathological jaundice. Conclusion: The present study found significant correlation between birth factors like antepartum haemorrhage, pregnancy induced hypertension, prematurity and pathological jaundice with autism. Further studies are needed to verify our findings, and investigate the effects of multiple factors on autism.