Background: Autism Spectrum Disorder (ASD) is pervasive and lifelong neurodevelopmental disorder characterized by impaired socialization, impaired verbal and nonverbal communication, and restricted interests and repetitive patterns of behaviour. The nurses’ level of understanding of Autism Spectrum Disorders can have a great impact on the prognosis of children with Autism Spectrum Disorder. This study is aimed at assessing knowledge of nurses about Autism spectrum Disorder. Objectives: To assess the level of knowledge among nurses regarding Autism Spectrum Disorder. Material and method: Quantitative Non Experimental research approach and   descriptive research design was used with 50 sample size.Tool consisted of demographic variables and structured questionnaire with 65 items related to Autism Spectrum Disorder under the following domains: meaning, diagnosis, causes, sign and symptoms and management. The data were analyzed with descriptive statistics wherever required. Results: Majority of nurses, 54% had poor level of knowledge related to Autism spectrum disorder, 35% of nurses had average level of knowledge and only 8% of nurses had good level of knowledge about Autism spectrum disorder. Conclusion: findings of the study projected well the level of knowledge of nurses about the Autism Spectrum Disorder. Majority of nurses had poor knowledge regarding Autism Spectrum Disorder.