Objective. To assess the knowledge and perception of primary school teachers regarding autism in private and public schools of Karachi, Pakistan. Methods. A cross-sectional survey was conducted on primary school teachers in different districts of Karachi. A sample size of 170 teachers was selected by purposive sampling. Primary data was collected using self-administered questionnaires. These questions assessed the teacher's knowledge and perception of Autism. Data was entered on SPSS version 20. Frequencies and percentages were taken out for categorical variables. Results. Of the total 170 teachers, 85 were from the Private and 85 from Public sector schools. 55% (n = 94) of the teachers knew about Autism through the media and only 9% (n = 15) had formal training through workshops on Autism. 62% (n = 105) of the teachers were of the opinion that Autism is treatable. Majority of the teachers (57%) said that proper training is required for teaching autistic children. Conclusion. The knowledge related to Autism in our existing sample has mostly come from the media. Although we cannot undermine the role of media, there is a need to give formal training to teachers regarding the differentiating features of Autism, which in turn will aid in early diagnosis of the disease.