In multiple studies, neuroticism and romantic relationship satisfaction are negatively related to one another. Yet, the exact behaviors that link neuroticism to lower relationship satisfaction are unknown. Our seven-day daily diary study (N = 246) identified specific, everyday behaviors that might mediate this association. After establishing positive and negative factors using exploratory factor analysis, we examined whether positive or negative behaviors (and sub-categories of these dimensions) mediate the relationship between neuroticism and relationship satisfaction. Our results showed that negative behaviors mediated the relationship between neuroticism and relationship satisfaction but positive behaviors did not. A subcategory of conflict tactics mediated the relationship over and beyond the mediational impact of the broader negative behaviors factor. There were no other mediational influences. The implications of this research can inform clinical interventions aimed at increasing relational functioning via a reduction in maladaptive relational behaviors associated with neuroticism.