Intimacy is vital to romantic relationships, yet is often thwarted by relational challenges, such as sexual difficulties. With prevalence estimates ranging from 10% to 28%, genito-pelvic pain/penetration disorder (GPPPD) is an important sexual problem resulting in negative consequences for affected women and their partners, including significant sexual dysfunction and dissatisfaction. Findings from cross-sectional studies indicate that higher levels of intimacy are associated with better sexuality outcomes in couples coping with GPPPD. However, single-occasion measurements may not capture the daily variations in intimacy that could have important implications for couples' sexual well-being. The present study focused on a key intimacy-building component-perceived partner responsiveness (PPR)-and its daily associations with women's pain and both partners' sexual function and satisfaction. Using daily diaries over an 8-week period, 160 women (Mage = 26.23, SD = 6.26) with GPPPD and their partners (Mage = 27.73, SD = 7.35) reported on PPR, sexual function and satisfaction, as well as women's pain, on days when sexual activity occurred (M = 8.87, SD = 5.87). Drawing on the Actor-Partner Interdependence Model, a multivariate multilevel modeling approach was adopted. Controlling for trait-level PPR, when women and partners reported greater PPR, women reported greater sexual function and satisfaction and partners reported greater sexual function. When partners reported greater PPR, they reported greater sexual satisfaction. No association was found between PPR and women's pain. PPR may facilitate better sexual function and satisfaction and could be an important target in sex and couple therapy for GPPPD. (PsycInfo Database Record (c) 2021 APA, all rights reserved).