Diabetes self-management is a challenging task due to its complexity and ever-present barriers to self-care. A key issue for patients, providers, and healthcare systems is how to deliver personalized behavioral support in ways that are affordable and can reach most patients. The Internet offers several advantages in this regard because it is available 24 hours a day, low cost, and capable of reaching thousands of patients. Although Internet sites for diabetes support are popular, they have not been evaluated. For this study, a Web site for diabetes self-management that emphasized personalized goal setting, feedback, and social support was developed. Over a 10-week period, 111 different persons logged onto D-NET for a total of 21,046 accesses. Users included persons across a broad age range (up to age 77 years) and duration of diabetes. The most popular areas of the site were the Social Support Conference and the Diabetes Information Pages. User ratings revealed high satisfaction with the service. The Internet has great potential for providing needed support and services for patients with diabetes and other chronic illnesses.