SYNOPSIS: Objective. The goal of this study was to identify determinants of maternal gatekeeping at the transition to parenthood. Design. Participants included 182 different-gender dual-earner couples. During pregnancy, expectant parents completed questionnaires regarding their psychological functioning, attitudes, and expectations, and at 3 months postpartum questionnaires regarding maternal gatekeeping behavior and gate-closing attitudes. Results. Structural equation modeling analyses revealed that mothers were more likely to close the gate to fathers when mothers held greater perfectionistic expectations for fathers’ parenting, had poorer psychological functioning, perceived their romantic relationship as less stable, and had higher levels of parenting self-efficacy. In contrast, fathers with lower parenting self-efficacy appeared to elicit greater maternal gate-closing behavior. Mothers who engaged in greater gate-opening behavior were more religious. Conclusions. Maternal gatekeeping may be more strongly associated with maternal expectations and psychological functioning than with maternal traditional gender attitudes. Fathers’ characteristics are less predictive of maternal gatekeeping than mothers’ characteristics.