The chytrid fungus Batrachochytrium dendrobatidis has contributed to declines and extinctions of amphibians worldwide. B. dendrobatidis is known to infect the frog Eleutherodactylus coqui in its native Puerto Rico. E. coqui was accidentally introduced into Hawaii in the late 1980s, where there are now hundreds of populations. B. dendrobatidis was being considered as a biological control agent for E. coqui because there are no native amphibians in Hawaii. Using a DNA-based assay, we tested 382 E. coqui from Hawaii for B. dendrobatidis and found that 2.4% are already infected. We found infected frogs in four of 10 study sites and on both the islands of Hawaii and Maui. This is the first report of B. dendrobatidis in wild populations in Hawaii. As the range of E. coqui expands, it may become a vector for the transmittance of B. dendrobatidis to geographic areas where B. dendrobatidis does not yet exist.