This issue of Endocrinology Clinics brings the reader up do date on the current standards and important advances in insulin therapy. The following clinical topics are discussed: types of insulins, including new insulins; goals of therapy; pathophysiology of, and insulin treatment in type1 and type 2 diabetes mellitus; pumps and glucose sensors; alternative insulin delivery; patient and provider insulin resistance; inpatient insulin therapy; insulin therapy in pregnancy; and pediatric insulin therapy.