Long-distance romantic relationships present unique challenges, necessitating couples to employ adaptive strategies to maintain intimacy and marital satisfaction. This study aimed to examine the validity of an adaptive model of sustaining behaviors in long-distance relationships and its capacity to predict marital intimacy and satisfaction. The model included mindfulness, sexual function, religious, and online social support domains. Data were collected online from 366 couples (aged 18 to 57; Mean = 34.82, SD = 7.34; 79.8 % female) engaged in long-distance relationships. A confirmatory factor analysis confirmed the acceptable fit of the four-factor model which was also invariant across gender groups. The results indicated significant associations between sustaining behaviors and marital intimacy and satisfaction, with varying predictive power among specific components. Notably, relationship/sexual mindfulness and marital sanction/religious communication within the religion domain emerged as robust predictors. Conversely, religious practice showed a significant negative association. Additionally, the realization component of the sexual function domain significantly predicted both marital satisfaction and intimacy, while its partnership component significantly predicted only marital intimacy. None of the social support components significantly predicted marital intimacy or satisfaction. These findings are important as they highlight the nuanced interplay between sustaining behaviors and relational well-being in long-distance relationships, emphasizing the need for tailored interventions to enhance relationship quality in this context.