Autism spectrum disorder (ASD) is a neurodevelopmental condition in which a child faces issues in communicating with other individuals and social interaction and showing repetitive behaviours and lack of interest. The diagnosis of ASD depends on an understanding of children’s developmental milestones. The developmental milestones serve as a useful indicator for parents and paediatric medical professionals to monitor the child’s growth from birth to age 5. Early screening and diagnosis of a child with ASD helps in managing it as soon as possible. Physiotherapy assessment plays a major role in assessing the child’s functional and mental status. Physiotherapy given as early care helps in improving the functional and mental status of a child with ASD. It also helps in improving the child’s social and communication skills as early as possible. It helps in overcoming functional and social challenges, as well as the quality of life in these children.