This lecture by Tracy Breen provides an introduction to the care of patients with Diabetes Mellitus Type 1. Clinical presentation, diagnostic strategies and evidence supporting the goals of glycemic control will be reviewed. The pharmacokinetics of the newer insulin analogs, different insulin delivery systems, and risk reduction strategies will be reviewed. At the end of this lecture, the listener should be able to differentiate Type 1 DM from Type 2 DM and to understand the basic philosophy of insulin therapy in patients with Diabetes Mellitus Type 1.