The purposes of this descriptive research were to explain self-care agency, quality of life, and relationships between self-care agency and quality of life, and examine the predictability of selected basic conditioning factors (personal factors such as educational background, family income, marital status, and religion, and health factors such as functional class, post-surgery complications, and period of time after surgery), on self-care agency and quality of life. The purposively recruited sample consisted of 100 post-open heart surgery patients. The instruments were: (1) a demographic data form, (2) a self-care agency questionnaire, and (3) a quality of life questionnaire. Data were analyzed using mean, standard deviation, correlation coefficient, and stepwise multiple regression. The results revealed that: (1) the mean self-care agency score was 5.22 (SD=.47), and the mean quality of life score was 24.54 (SD=2.94), (2) there was a significant positive relationship between self-care agency and quality of life (r=.59, p < .01), (3) two significant predictors could explain fourteen percent of the variances in total self-care agency scores: patients' functional class and family income (p < .05), and (4) two significant predictors could explain twenty-three percent of the variances in total quality of life scores: post surgery complications and period of time after surgery (p < .05).