As one of four major causes of death in Korea, diabetes mellitus has dramatically increased since the 1980s because of westernized lifestyles. Diabetes patients try to learn the knowledge and skills necessary for disease care since diabetes management is highly dependent on self- management. To do this, patients pursue more health information and proper sources for themselves. This study developed an evaluation tool including categories with items necessary for evaluation of Websites for health information on diabetes mellitus, as a method to offer consumers certified high quality health information on diabetes.