The present study examined the effects of predatory odor (cat urine) on social novelty preference in Long-Evans rats. Adult male subjects encountered a juvenile conspecific at training, were exposed to either clean cat litter (control) or litter soiled with cat urine (predatory odor), and were tested for social novelty preference. While the predatory odor and control groups did not differ in exploration of the initial conspecific at training or in the investigation of both the novel and familiar conspecifics at test, animals exposed to predatory odor prior to test spent a smaller percentage of their exploration time investigating the novel conspecifics than did controls, suggesting that predator odor is capable of disrupting social novelty preference. (Contains 1 table and 1 figure.)