Although diabetic ketoacidosis should, theoretically, be largely preventable in patients with established diabetes, a recent report from a major US childhood diabetes center showed that children with type 1 diabetes remain at high risk for diabetic ketoacidosis, with an incidence of 8 per 100 patient-years. Children who are uninsured or underinsured, have psychiatric disorders, have poorly controlled diabetes, and live in dysfunctional families are most vulnerable. The efficacy and cost effectiveness of strategies to reduce the incidence of diabetic ketoacidosis-before diagnosis and in patients with established diabetes-are important issues for future investigation.