Incidence,prevalence,and densityof ectoparasites are reported for 3 species of tropical bats,Stenoderma rufumDemarest,Artibeus jamaicensisLeach,Monophyllus redmaniLeach, from the tabonuco forest of Puerto Rico. In addition,patterns of ectoparasite associations were examined with respect to several host characteristics including age and sex, as well as with respect to season. Levels of ectoparasite infestation differed because of host age, but not sex,with juveniles harboring higher numbers than adults. No ectoparasite attribute differed with season. Significantly different assemblages of parasites occurred on adult male, adult female, and juvenileA. jamaicensis. Moreover,S. rufum, A. jamaicensis, andM. redmanieach have a significantly different ectoparasite assemblage.