Caregivers support heart failure (HF) self-care with little HF education. The purpose of this study was to evaluate the effectiveness of a caregiver-only educational intervention aimed at improving caregiver self-efficacy, perceived control, and HF knowledge, as well as patient self-care and 30-day cardiac readmission. In total, 37 patients and their caregivers were randomly assigned to a control condition or a caregiver-only educational intervention with telephone follow-up. Outcomes included patient 30-day cardiac readmission, patient self-care, caregiver self-efficacy, caregiver perceived control, and caregiver HF knowledge. Linear mixed model, Kaplan-Meier, and Cox regression analyses were used to determine the effects of the intervention on outcomes. Self-care maintenance ( = 0.002), self-care management ( = 0.005), 30-day cardiac readmission ( = 0.003), and caregiver perceived control ( < 0.001) were significantly better in the intervention group. The results suggest that interventions targeting caregiver HF education could be effective in improving HF patients' 30-day cardiac readmissions, patient self-care, and caregiver perceived control.