Although there are some interactions between the major pediatric diabetes programs in the United States, there has been no formal, independent structure for collaboration, the sharing of information, and the development of joint research projects that utilize common outcome measures. To fill this unmet clinical and research need, a consortium of seven pediatric diabetes centers in the United States has formed the Pediatric Diabetes Consortium (PDC) through an unrestricted grant from Novo Nordisk, Inc. (Princeton, NJ). This article describes the organizational structure of the PDC and the design of a study of important clinical outcomes in children and adolescents with new-onset, type 1 diabetes mellitus (T1DM). The outcomes study will describe the changes in A1c levels, the frequency of adverse events (diabetic ketoacidosis/severe hypoglycemia), and the frequency and timing of the "honeymoon" phase in newly diagnosed patients with T1DM over the first 12-24 months of the disease and examine the relationship between these clinical outcomes and demographic, socioeconomic, and treatment factors. This project will also allow the Consortium to develop a cohort of youth with T1DM whose clinical course has been well characterized and who wish to participate in future clinical trials and/or contribute to a repository of biological samples.