During cardiac surgery postoperative care, physical, psychological, and social problems arise, affecting the patient's self-care agency, which brings with it the need for a caregiver during recovery. To determine the relationship between primary caregivers' burden level and the self-care agency of cardiac surgical patients. A descriptive, cross-sectional, analytical, and correlational design was used. Patients (n=86) and caregivers (n=86) attending a cardiac surgery program from a high complexity medical center in Cúcuta, Colombia, participated and were selected using non-probability quota sampling. Self-care Agency Scale (SAS) and Zarit Burden Interview were used in the study. Among the caregivers with severe burden, 83.33% cared for patients with low self-care agency. In the mild-burden caregivers' group, 63% of the patients had middle self care agency. Most patients (71.01%) of caregivers with no burden had middle self-care agency, but 20.29% exhibited high self-care agency. the capacity for self-care agency reduces the level of caregiver burden, when the patient manages to adapt to the activities that contribute to care, the level of dependency decreases. The research demonstrated the relationship between these two variables. Patients and caregivers must be addressed to achieve self-care empowerment.