OBJECTIVE To report results from YourWay, an Internet-based self-management intervention for adolescents with type 1 diabetes. RESEARCH DESIGN AND METHODS A total of 72 adolescents with type 1 diabetes, ages 13-17 years, were randomized to a usual-care-plus-Internet support or a usual-care group. The intervention was designed to enhance problem-solving barriers to self-management. A1C was obtained from medical records, and problem-solving and self-management were obtained via adolescent report. RESULTS Group differences were not statistically significant using intent-to-treat analyses. Using as-treated analyses, adolescents in the treatment condition showed statistically significant improvement in self-management (d = 0.64; P = 0.02) and important improvements in problem-solving (d = 0.30; P = 0.23) and A1C (d = -0.28; P = 0.27). Mean A1C for the intervention group remained constant (-0.01%), while the control group increased (0.33%). CONCLUSIONS This brief trial suggests that self-management support delivered through a secure website may improve self-management and offset typical decreases in adolescent glycemic control.