Background: The majority of heart failure (HF) self-care research remains focused on patients, despite the important involvement of family caregivers. Although self-care confidence has been found to play an important role in the effectiveness of HF self-care management on patient outcomes, no known research has examined self-care confidence within a dyadic context. Objective: The purpose of this study was to identify individual and dyadic determinants of self-care confidence in HF care dyads. Methods: Multilevel modeling, which controls for the interdependent nature of dyadic data, was used to examine 329 Italian HF dyads (caregivers were either spouses or adult children). Results: Both patients and caregivers reported lower-than-adequate levels of confidence, with caregivers reporting slightly higher confidence than patients. Patient and caregiver levels of confidence were significantly associated with greater patient-reported relationship quality and better caregiver mental health. Patient confidence in self-care was significantly associated with patient female gender, nonspousal care dyads, poor caregiver physical health, and low care strain. Caregiver confidence to contribute to self-care was significantly associated with poor emotional quality of life in patients and greater perceived social support by caregivers. Conclusions: Findings are supportive of the need for a dyadic perspective of HF self-care in practice and research as well as the importance of addressing the needs of both members of the dyad to maximize optimal outcomes for both.