The psychological characteristics of ego functions interfere with self-care behavior in several diseases. However, the effect of ego functions on self-care behavior after education in heart failure (HF) remains unclear. Seventy-one HF patients were enrolled. Patients' scores on the Japanese version of the European Heart Failure Self-care Behaviour Scale (EHFScBS) were measured before and after the HF intervention, and the rate of change was used as an indicator of educational effectiveness. The Tokyo University Egogram New Ver. II was used to assess five types of ego state functions: Critical parent, Nurturing parent, Adult, Free Child, and Adapted Child (AC). A comparison of the five ego states showed that AC scores were significantly lower than those of the other ego states (p < 0.01). Total EHFScBS scores significantly decreased from 33 (26-39) to 16 (14-20) (p < 0.01) after the HF education, and the median rates of change in EHFScBS was -46.2%. Patients with a lower rate of change in EHFScBS were more likely to have low AC scores, as characterized by a lack of compliance and coordination, and were less likely to receive higher education (all p < 0.05). Even after adjustment for covariates, low AC scores were independently associated with low rate of change in EHFScBS (p < 0.01). Educational behavior change for self-care is less effective in HF patients with an ego state with low AC.