Mate choice based on age and body size is poorly understood among cervids. We used 14 microsatellite DNA loci to assign parentage and reconstruct the pedigree of a captive population of white-tailed deer (Odocoileus virginianus) in order to evaluate their mate choice and reproductive success. From 2008 to 2013, we assigned both dam and sire to 87 litters. Age differences between mated pairs did not differ from random pairings and we found no apparent relationship of skeletal size between pairs. Our results highlight the plasticity of mating success for white-tailed deer and we speculate their mating system has evolved to maximize fertility. Our investigation was the first to explore mated pairs of white-tailed deer with such a high proportion of candidate parents sampled and the first to incorporate vaginal implant transmitters to validate genetic sampling techniques. This knowledge could help local and regional wildlife managers comprehend the unpredictability of mating success of whitetailed deer.