The aim of this report is to describe four cases of non-autoimmune diabetes that presented in infancy. Three had transient neonatal diabetes mellitus (TNDM) with diabetic ketoacidosis at onset, followed by complete remission after several months of insulin treatment. While the fourth case was initially diagnosed as TNDM, she had renal, hepatic and pancreatic dysplasia. These cases illustrate that diabetes in infants can be difficult to diagnose and that patients with TNDM can have a recurrence of diabetes several years later.