Experiments were designed to investigate variables that may be essential for the establishment of sexual discriminations by male and female golden hamsters. It was demonstrated that heterosexual contact experience of females is not an essential prerequisite for their ability to discriminate between males and females as adults. Males that had made physical contact with an alternate estrous hamster immediately prior to testing were found to be significantly more attractive to estrous hamsters than unprimed males. A past record of copulatory experience did not necessarily render males more attractive than sexually naive males. Whereas lordosis, tonic immobility, and maintenance of physical proximity served as measures of female sexual preference, flank marking by females against the cages confining hamsters did not serve as such a measure. Intact male hamsters reliably discriminated between an intact estrous hamster and an untreated overiectomized one only after they had contacted an alternate estrous hamster prior to testing. Male sexual discrimination between an intact estrous and an intact diestrous hamster was shown only when the stimulus females had been primed immediately prior to the test trial by allowing them to physically contact an alternate male. Upon simultaneous presentation of estrous vs diestrous vaginal secretions, intact males preferred to spend more time licking and sniffing the estrous sample in 50% of the test trials. However, only 10 sec more time was spent on average with the estrous sample. It is concluded that male hamsters probably rely more on a combination of visual, tactile, chemosensory, and auditory cues rather than solely on olfactory stimuli to discriminate between a sexually receptive and nonreceptive hamster. Furthermore, the strength of the cues appear to vary as a function of recent heterosexual contact.