This study aimed to examine the effect of pre-operative information by audiovisual media on patients before bariatric surgery. Methods: This study was conducted from July 4 to October 25, 2019 at Busan city in South Korea. Non-equivalent control groups with quasi-experimental design were used. A total of 24 patients were assigned to the experiment group (n=12) and the control group (n=12). Experimental tools provided information using audiovisual media, including a seven-step introduction of video contents. After that, the investigator used a Universal Serial Bus (USB) to transmit the "Obesity Escape" program to the electronic devices (smartphones, laptops, etc.) belonging to the patient or guardian, and then provided a self-learning checklist. The subjects self-learned through reviewing the items in the checklist at least three times each day at home for a total of two weeks until the day of re-admission until discharge. The investigator provided encouragement and counseling by phone once a week (every Friday). Results: There were significant differences between the two groups in the preoperative self-care (p<.001) and preoperative self-efficacy (p=.001), and preoperative state anxiety (p=.036). Conclusion:The results of this study suggest that the use of audiovisual media can be actively used in the nursing practice field to increase preoperative self-care and preoperative self-efficacy and reduce preoperative state anxiety in patients before bariatric surgery.