Despite exciting advances in our awareness and understanding of autism spectrum disorder (ASD), there has been relatively little progress in prevention of this form of neurodevelopmental disorder, or in the development of evidence-based practices to improve outcomes for people with ASD and their families. In addition, most of what is known about the epidemiology, genetics, clinical manifestation and course, treatment, and nearly every other aspect of autism is based on research in high income countries, where fewer than 10% of births occur and less than 20% of the population lives globally. Maureen Durkin, director of the Graduate Program in Population Health at the University of Wisconsin-Madison School of Medicine and Public Health, reviews some of the recent developments in the epidemiology of ASD and describe opportunities to expand the horizons of ASD epidemiolog. (#28483)