(Uploaded by Plazi for the Bat Literature Project) We developed ten dinucleotide and four tetranucleotide microsatellite markers for two species of tree bats from the family Vespertilionidae that are experiencing high mortality at wind energy facilities. Eleven of these loci were polymorphic in eastern red bats (Lasiurus borealis), whereas nine loci were polymorphic in hoary bats (Lasiurus cinereus). The number of alleles per locus ranged from 2 to 29 (mean = 14 alleles) and observed heterozygosity was generally high (mean 0.754, range 0.125–0.979). This set of microsatellite markers will be useful for studying population structure of these bats as part of a larger effort to understand the potential impacts of wind energy development on their populations.