This study was conducted to evaluate the effectiveness of support group intervention applied to the caregivers of individuals with heart failure on caregiver outcomes. Quasi-experimental research was conducted with 69 caregivers as control (n = 35) and intervention (n = 34) groups in the cardiology outpatient clinic of a university hospital. The intervention group participated in support group meetings structured according to the Neuman Systems Model, and the data were collected from both the intervention and control groups before the intervention and 3 and 6 months later. Caregivers in the intervention group had significantly lower burden scores compared with the control group in all subdimensions except objective personal care, in terms of the group × time interaction in a statistical way (P < .05). Caregivers in the intervention and control groups had similar scores of depression symptoms (P > .05). The burden of caregivers in the intervention group showed a statistically significant decrease compared with the preintervention in all dimensions at 3 months. Thus, it is suggested to extend the support group interventions for caregivers of patients with heart failure and conduct these interventions in a longer period.