This study sought to elucidate self-care, self-monitoring, and related factors among outpatients who underwent coronary artery bypass graft (CABG) surgery within the previous 12 months, and to discuss important fundamental issues regarding educational support provided by nurses to inpatients. A questionnaire survey was mailed to participants who responded anonymously. Each item was analyzed by simple tabulation and relations between the items were analyzed by cross tabulation. Of 52 surveys sent, 36 responses were obtained. Execution rates of self-monitoring were 75.0% for body weight measurement, 55.6% for blood pressure measurement, 47.2% for taking own pulse, 19.4% for recording number of daily steps, and 2.8% for recording contents of each meal. The three main reasons that participants did not self-monitor these five elements were “do not have a measurement instrument”, “feel it is unnecessary to self-monitor”, and “difficult or bothersome to record the results”. The top three responses for the self-care execution rates were “I go up and down stairs at my own pace”, “I try to eat vegetables with every meal” and “I take my time when doing something”. These findings suggest that it is important for nurses who care for inpatients who have undergone CABG to help patients clearly establish the frequency and timing of measuring their body weight and taking their blood pressure and pulse after discharge. Also, nurses should help such inpatients realize the importance of self-care after discharge in terms of exercise and diet, including regular measuring or recording of these parameters.