Continuous subcutaneous insulin infusion (CSII) was first introduced as a mode of treatment for persons with type 1 diabetes mellitus (T1DM) in the late 1970s. Since that time, there have been many reports and reviews of this modality of treatment in adults and adolescents with diabetes and several reports of the use of this technology in the treatment of children with T1DM. Conflicting data have accumulated on the consistency of improvement in hemoglobin A1c (HbA1c) and in the frequency of complications, most significantly that of hypoglycemia. Some studies report the findings of controlled randomized studies, but many of these studies were conducted on small numbers of highly selected patients. Some studies are prospective but not randomized, where subjects pre-CSII serve as their own controls. Yet other studies are retrospective reviews of children and adolescents who have been treated with CSII. This paper reviews what has been learned about patient selection and outcomes of CSII treatment, with the goal of outlining steps in the selection and preparation of patients for CSII that will facilitate optimum outcome.