Oxytocin is a short peptide with multiple functions in human biology and has been implicated in autism. We aimed to determine the normal pattern of variation around the oxytocin gene and resequenced it and its flanking regions in 91 individuals from four HapMap populations and one chimpanzee. We identified 14 single nucleotide polymorphisms (SNPs), all noncoding, including eight that were novel. Population genetic analyses were largely consistent with a neutral evolutionary history, but an Hudson-Kreitman-Aguadé (HKA) test revealed more variation within the human population than expected from the level of chimpanzee-human divergence.