Heart failure (HF) is a chronic and progressive syndrome of cardiac impairment, affecting nearly 6 million U.S. adults. Four out of every ten persons with HF will die within 5-years of the first acute hospitalization and prevalence is expected to increase substantially. Managing HF requires the routine practice of self-care and may be influenced by family and friend caregivers. Self-care is a process of maintaining health through health promoting practices and managing illness. Interpersonal factors that may influence HF self-care include caregiver autonomy support, relationship quality and dyad gender. Caregiver autonomy support is a dynamic behavioral process whose purpose is to empower the adult with chronic illness to make fully informed, self-determined choices. Relationship quality is characterized by satisfaction, gratification or meaning between the person with illness and their caregiver. Dyad gender represents a multidimensional relation between individual dyad members, social, and structural processes. Despite their significance to self-care, little is known about characteristics that may make caregivers more or less effective in their roles. This dissertation will examine the characteristics of autonomy support, relationship quality and dyad gender in the effective support of self-care. Article 1 systematically reviews and synthesizes results of caregiver autonomy support interventions for chronic illness. Articles 2 and 3 use data from an intervention that incorporates principles of autonomy support (motivational interviewing) for HF. Article 2 employs logistic regression on longitudinal data to determine characteristics impacting response to motivational interviewing. Article 3 examines dyad gender and relationship quality in HF self-care using linear regression on baseline data. Characteristics impacting response to autonomy support included non-ischemic HF etiology, living alone, fewer medications, and relatively higher baseline self-care. Dyad gender was associated with HF self-care for male-male and female-female dyads. Better caregiver relationship quality in these dyads contributed to an additional decrease in patient self-care. Results suggest a relationship between autonomy support and HF self-care. Self-care behaviors may be strengthened through skills-based interventions targeting caregiver autonomy support. Relationship quality and dyad gender may interact to affect self-care, particularly in similar-gender dyads. Results may lead to more effective clinical practice and new research opportunities.