<p>The purpose of this study was to better understand the impact of insecure attachment (i.e., avoidant and anxious) on neuroticism and relationship quality (i.e., satisfaction and stability) with couples in serious dating relationships. We analyzed cross-sectional data from 1253 straight dating couples who completed the RELATionship Evaluation (RELATE) questionnaire online using actor-partner interdependence path modeling with neuroticism as an intermediary variable. For both female and male partners, avoidant attachment and anxious attachment predicted their own neuroticism, relationship satisfaction, and relationship stability. Similarly, neuroticism predicted relationship satisfaction and relationship stability. Moreover, male avoidant attachment predicted female relationship satisfaction but not stability, female anxious attachment predicted male relationship stability but not satisfaction, and male anxious attachment predicted both female relationship satisfaction and stability. In addition, female neuroticism predicted male relationship satisfaction but not male stability, whereas male neuroticism did not predict female relationship satisfaction or stability. In terms of indirect effects, partners own neuroticism partially explained the associations between their own insecure attachment and relationship quality for both females and males. Gender differences emerged in the indirect effects on relationship satisfaction, with female partners’ avoidant and anxious attachment significantly reducing male partners’ satisfaction through female neuroticism; there were no similar crossover indirect effects for female partner satisfaction, and no crossover indirect effects for either gender for relationship stability. Emotionally Focused Therapy is suggested as a treatment approach to explore attachment histories, offer corrective emotional experiences, and address the impact of traits associated with neuroticism for clinicians working with dating couples. </p>