INTRODUCTION: Fibromyalgia is a disease that impacts the daily lives of patients and their partners with an impact on quality of life (QoL) and marital adjustment. The purpose of this study was to analyze the relationship among sociodemographic, clinical, and psychological variables on QoL and marital adjustment. METHOD: This cross-sectional study included patients ( RESULTS: Pain control beliefs had an indirect effect in the relationship between psychological morbidity and marital adjustment and between family coping and marital adjustment, and a direct effect in the relationship between psychological morbidity/fatigue severity and QoL and between family coping and marital adjustment, revealing an indirect effect in this latter relationship. Also, the dyadic analysis showed an actor effect between family coping and marital adjustment of both patients and partners and a partner effect between family coping in partners' and patients' marital adjustment. DISCUSSION: The results of this study underline the need for interventions to address the dyad and be focused on pain beliefs and on the importance of family coping to promote patients and partners' marital adjustment and QoL. (PsycInfo Database Record (c) 2025 APA, all rights reserved).