An albino male Microtus pennsylvanicus, live-trapped in an old-field community in Butler County, Ohio, was successfully bred with four conspecific wird-type females in the laboratory. Individuals from the resulting generations were bred with nonlittermates of the same generation or previous generations. This case of albinism was shown to be inherited as an autosomal recessive trait. No significant differences were observed between litter sizes of voles bred in an experimental albino colony and those bred in a separate wildtype colony. Homozygous albino offspring, however, exhibited a significantly lower body mass than homozygous and heterozygous agouti offspring at 20 days of age.