- The vast majority of autism spectrum disorder (ASD) research focuses on Caucasian populations in western world countries. While it is assumed that autism rates are similar across ethnic groups regardless of genetic background and environmental exposures, few studies have specifically examined how autism prevalence and severity may differ between majority and minority populations with distinct characteristics. Therefore, we evaluated ethnic differences in ASD prevalence and severity of Bedouin-Arab and Jewish children in the south of Israel. We compared demographic and clinical characteristics of 104 children from a Bedouin-Arab minority with 214 Jewish children who were referred to the main ASD clinic in Southern Israel with suspected communication disorders. Data were obtained from medical records. Jewish children’s referral rates were almost 6 times more than that of Bedouin-Arab referral rates (21:1000 and 3.6:1000, respectively). The percentage of high functioning children with ASD was much higher in Jewish than in Bedouin-Arab children (29.6 and 2.6%, respectively). Bedouin-Arab children showed more severe autistic manifestations. Moreover, Bedouin-Arab children were more likely than Jewish children to have additional diagnosis of intellectual disability (14.5 and 6.9%, respectively). Autism prevalence and severity differs markedly between the Bedouin-Arab and Jewish populations in the south of Israel. Most striking is the almost complete absence of children with high-functioning autism in the Bedouin community. A better understanding of the causes for autism prevalence and severity differences across ethnic groups is crucial for revealing the impact of multiple genetic and environmental factors that may affect autism development in each group.