Diabetic ketoacidosis remains one of the most serious acute complications of diabetes mellitus. The mortality rate is < 5 % with modern management strategies. The mainstay of treatment for this condition includes the following: Hydration, insulin therapy, correction of electrolyte abnormalities, and treatment of the underlying precipitating factors. While several advances have been made with the type and delivery of insulins, controversy and confusion surround the prescription of optimal fluid therapy in diabetic emergencies. The focus of this commentary is to examine the evidence base for the choice of resuscitation and maintenance fluid in diabetic ketoacidosis.