A critical analysis of the evolution during the first 24 hours was undertaken in 41 children and adolescents (age: 10.1 +/- 4.6 years) treated for diabetic ketoacidosis. Three of 4 children presented with ketoacidosis revealing diabetes. One of 4 was less than 6 years of age. Severe ketoacidosis (pH less than 7.15) concerned one third of children and were more frequent in the group of adolescents with already known diabetes. In these patients, ketoacidotic decompensation was attributed to psychosocial factors in most cases. Evolution was favorable in all cases, without complication. Blood glucose levels decreased from 28.7 mmol/l on arrival to 16.2 mmol/l after 2 hours of treatment and became stable at 10 mmol/l from the 12th to the 24th hours. The corrected blood sodium levels were stable, showing the adequacy of infusion solute osmolarities. Blood potassium was maintained at a normal level owing to early potassium supplementation. Ketoacidosis was corrected after about 12 hours, without bicarbonate administration when pH was greater than 7.15. Average perfused volumes were 3 l/m2/24 hours. Insulin doses were 2 UI/kg/24 hours and were inversely correlated with the admission pH (r = -0.6; p = 0.0001). This study shows the efficacy of a treatment taking into account the pathophysiology of diabetic ketoacidosis and the knowledge of the complication risk factors, by foreseeing the adjustments to be done with respect to individual and/or at risk situations. These precise descriptive data, collected on a large group of patients, establish a reference basis to follow evolution in the course of the treatment of diabetic ketoacidosis in children.