Abstract Urine preferences of adult wild male guinea pigs reared with domestic female guinea pigs were studied. Subjects were removed from the mothers at birth and each was reared with a domestic female for either the first 3 or the first 16 weeks of life; each control group male was reared with a wild female for the first 3 weeks of life. Following rearing experience, males were reared in social isolation. A series of urine preference tests was conducted beginning when the subjects were 17 weeks of age. Whereas males in the control group preferred urine of wild animals to urine of domestic animals, individuals reared with a domestic female generally preferred domestic female urine to wild female urine and were equally attracted to male urine of the two species. It is concluded that postnatal prepubertal experience influences urine odor preferences in wild male guinea pigs.