In chronic obstructive pulmonary disease, impairments of dyadic coping are associated with reduced quality of life. However, existing studies have a cross-sectional design. The present study explores changes in dyadic coping over time and its long-term effects on quality of life of both patients suffering from COPD and their partners. Dyadic coping, psychological distress, health-related quality of life, and exercise capacity were assessed in 63 patients suffering from COPD with their partners, at baseline and 3-year-follow-up. Correlation analyses and actor-partner interdependence models (APIMs) were conducted. Patients' delegated dyadic coping (taking over tasks) and common dyadic coping (mutual coping efforts when both partners are stressed) rated by the spouses decreased. Correlation analyses showed that patients' quality of life at follow-up was positively influenced by partners' stress communication (signaling stress). Partners' quality of life at follow-up was negatively influenced by patients' negative dyadic coping (reacting superficially, ambivalently or hostilely) and positively influenced by partners' delegated dyadic coping rated by patients (taking over tasks). APIMs mostly supported these results. It seems important that both partners communicate about stress and provide appropriate instrumental and emotional support to maintain quality of life.