There is ample evidence that inbreeding, or mating between relatives, can lead to increased homozygosity and decreased fitness. However, some animals have evolved mechanisms to avoid inbreeding. In a previous study of the National Bison Range, Montana, pronghorn Antilocapra americana, we detected moderate levels of inbreeding, as well as inbreeding depression, following a bottleneck. Here, we evaluated whether there was genetic evidence of inbreeding avoidance in pronghorn. We found that females were more related to all males in the population than they were to their mates, suggesting that pronghorn can avoid inbreeding. However, relatedness between females and the males they sampled prior to estrus did not differ from relatedness between females and all males, nor from relatedness between females and their mates. Inbreeding avoidance appears to occur during the female estrus period rather than during the female mate sampling period. Further work is needed to discover the sensory cues that female pronghorn use to avoid mating with relatives.