OBJECTIVE: This study assessed the effects on type 2 diabetes self-management education provided in group courses with or without a supporting smartphone application (the DM2CUA app). RESEARCH DESIGN AND METHODS: This open-label, cluster-randomized, controlled, multicenter pilot study involved three Austrian diabetes educational group courses. People with type 2 diabetes in the control group received a regular educational group course, whereas those in the intervention group received the same course plus the use of the DM2CUA app. The app prompted participants to carry out educational tasks that were discussed in the course. After the last lesson, the app provided participants with relevant messages for another 4 weeks. The primary outcome measure was the Diabetes Self-Management Questionnaire score assessed at four time points. Secondary outcome measures included scores on the Diabetes Distress Scale and the Health Education Impact Questionnaire and A1C levels. RESULTS: Participants in the intervention group already had a higher level of diabetes self-management at the start, but the median score showed further improvement during the entire study period. CONCLUSION: Findings from this pilot study suggest that the DM2CUA app may have a positive impact on diabetes self-management.