An analysis of 1000 cases of diabetic ketoacidosis has suggested to the authors their classification into four evolutive stages: incipient ketoacidosis (normal pH, decrease of total CO2, between 20--26 mMol/l and of excess bases between -2 and -5 mMol/l), moderate ketoacidosis (pH 7.31-7.35, total CO2, between 15--19.9 mMol/l, excess bases between -5 and -10 mMol/l); advanced ketoacidosis, "diabetic precoma" (pH 7.21-7.30 total CO2 between 11 and 14.9 mMol/l, excess bases between -10 and -15 mMol/l, and severe diabetic ketoacidosis or "diabetic coma" (pH less than or equal to 7.20, total CO2 less than or equal to 10 mMol/l, excess bases greater than -15 mMol/l). The follow up of the four therapeutical parameters (number of hours, amount of fluids, insulin and KCl necessary for equilibration) showed that this classification of ketoacidosis reflects the degree of metabolic and hydroelectrolytic disorders, suggesting at the same time the intensity of the treatment to be administered in view of correcting them.