Research exploring the mechanisms by which specific genes contribute to overall marital quality is still in its beginning stages; however, one mechanism may be the link between the oxytocin receptor gene (OXTR) and behavioral deficits relevant to social support-a critical determinant of marital quality. Using 79 different-sex married couples (N = 158), we found that genotypic variation in single nucleotide polymorphisms (SNPs) on wives' and husbands' OXTR variously associated with husbands' and wives' support provision and receipt behaviors in social support discussions. We also found significant indirect effects of husbands' TT genotype for OXTR SNP rs1042778 on lower marital quality for husbands and wives by way of the husband's more negative evaluation of his wife's responsiveness when he was the target for support. However, exploratory analyses also revealed that this genotype conferred benefits to marital quality through another path, altogether supporting the notion that genotypic variation on OXTR may have broad and potentially context-dependent influences on social behavior, which may play out in complex ways when examined in a marital context. (PsycINFO Database Record (c) 2019 APA, all rights reserved).