Introduction:Autism spectrum disorders (ASD) is a group of heterogeneous neurodevelopmental disorder characterised by deficits in social communication and the presence of restricted interest and repeated behaviours.The prevalence across the world is 16%. It is more common in males. Despite the global increase in the prevalence of ASD relevant research studies are lacking in India. Hence the study aims at early detection of autism by using 2D:4D ratio as a potential screening tool. Methods:The study included 23 (cases) male children in the age group of 3 to 9 years diagnosedwith ASD using Indian Scale for Assessment of Autism (ISAA) and 20 controls. The length of both second digit and fourth digit fingers in both cases and control wereobtained and compared. Results:Analysis of the grades of Autism showed that most of the children had moderate autism 47.8%. On Comparison of 2D:4D ratio with grade of autism showed that mild, moderate and severe autism had SD score of 0.013, 0.017, 0.18 respectively with a p value of 0.57. On comparing the mean 2D:4D ratio between the cases and control group showed a statistically significant association with the cases with p value of <0.001.