Emerald ash borer (EAB), Agrilus planipennis Fairmaire, was first identified as the cause of ash, Fraxinus spp., mortality in Michigan and Canada in 2002. Efforts to eradicate this destructive pest by federal and state regulatory agencies are frustrated by a lack of detection methods and the magnitude of the problem. Knowledge of EAB genetics will be useful in understanding the invasion dynamics of the beetle and to help identify geographic localities of potential biocontrol agents. To this end, EAB were collected from localities in Michigan, Indiana, Ohio, Ontario, Japan, South Korea, and China. We found the DNA sequence of mtDNA cytochrome oxidase subunit I (COI) were identical for all individuals except for a sample from Japan, which differed by 3.7%. Differences between individuals and populations were observed using amplified fragment length polymorphisms (AFLP). AFLP analysis based on four primer pairs yielded 139 scoreable bands, which showed most individuals from North America cluster with individuals from China while the EAB individual from Japan fell into a separate, more distantly related group. Nonetheless, more thorough sampling throughout Asia is necessary to better characterize the relationships of the North American populations and Asian populations since Asian populations are based on very few individuals. Due to the rarity of EAB in Mongolia, Taiwan and Russia, no samples have yet been found for genetics.