We live in an era of exciting advances in our awareness and understanding of autism spectrum disorder, but also a time of enormous global imbalance. 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. This talk will describe opportunities to expand the horizons of autism epidemiology and service delivery to include the 80 to 90% of affected individuals and families who live in low and middle income countries, as well as those who are socioeconomically disadvantaged and living in high income countries. It will also describe some of the cultural and financial barriers to progress, and make a case for incorporating concepts of the World Health Organization's International Classification of Disability and Functioning into the classification and epidemiology of autism spectrum disorder, with the ultimate goals to include not only primary prevention of autism but also enhancement of participation and social inclusion of people with autism spectrum disorder.