Introduction: Providing self-management education for residents with cardiometabolic conditions in remote islands is a challenge due to the shortage of primary care practitioners (PCPs), specialist physicians, and nurses. Therefore, we applied telenursing with lifestyle-related chronic diseases in remote island residents in Japan. This project aimed to improve the self-management behavior, cardiometabolic indicators, self-efficacy, and quality of life (QoL) of residents with cardiometabolic risks. Methods: We chose Ōsakikamijima Island, Hiroshima Prefecture, Japan, which is designated under the Remote Islands Development Act. The project was conducted from 2013 to 2014. The residents aged over 40 and under 75 years old, selected from the annual specific health check-up examination and from PCPs for screening cardiometabolic risks (urinary protein, glycohemoglobin A1c, systolic and diastolic blood pressure (BP), Low-density lipoprotein cholesterol, High-density lipoprotein cholesterol, and triglyceride) were included. The effectiveness of telenursing for self-management education was 6-month-long with a 6-month follow-up and evaluated by a single-group pre-and post-test design. Face-to-face health education was applied at the initial interview followed by telenursing (biweekly telephone calls till third-month, and a monthly telephone call during the fourth and fifth-month) by the trained nurses outside the island. To enhance participants’ self-monitoring health behavior changes, the nurses used motivational interviewing and behavior change techniques based on the transtheoretical model. Results: A total of 130 residents, 42 agreed to participate, 41 finished the 6-month program, and 33 completed the 12-month follow-up. Most of their behavior changes like self-management behaviors, cardiometabolic indicators, and self-efficacy at 6-month were improved significantly except QoL. Among the 12-month study periods, self-management behaviors, body mass index, systolic BP, diastolic BP, and self-efficacy (sense of control), (all P < .05) showed significant improvement. Conclusion: This study results indicated that telenursing might be effective to improve the lifestyles-related behaviors in chronic diseases on the remote island of Ōsakikamijima, Japan.