Autism is an advanced neurogenic disease condition with specific neurodevelopmental characteristics and deficiency in social relations and interaction, as well as limited rhythmic and stereotyped patterns of actions that habitually arise in the toddler stage of life. Mothers of children with autism were found to have greater levels of childcare-associated stress. This study aims to determine mothers' general knowledge of autism. A cross-sectional study was conducted among the mothers of autistic children in Al Ahsa, Saudi Arabia, between 20 September and 20 December, 2019. The study included 63 mothers of autistic children. A 29-items questionnaire was created following a wide-ranging literature review. A pilot study was conducted on 20 mothers to assess the simplicity and understanding of the questionnaire. The data indicated that more than two thirds, i.e. 44(69.8%) of all respondents had a low level of or insufficient knowledge about autism, 19(30.2%) had a medium level, while none had a high level of knowledge. The results showed that the mother's job, the child's age, and the child order variables were important predictors, and the value was statistically significant at (α = 0.05) for the mothers' knowledge level. It could be concluded that Al Asha's mothers' children with autism lack the perception and knowledge of the signs and symptoms. Mothers were also found to need awareness programs for diagnosis and treatment approaches.