We retrospectively reviewed the charts of 550 patients of less than 19 years of age with cyto-histological diagnosis of malignancy, admitted from January 1979 to December2000. Retrieved data included: time from the beginning of symptoms to first consultation (family delay), time from first medical consultation to reference to the specialized Centre (with or without diagnosis of tumor disease) (Medical delay) and time from admission at the Reference Centre to diagnosis (Reference Centre delay). Of the grand total of 550 patients 204 (36%) belonged to group A (1979-89) and 346 (64%) to group B (1990-2000). Of these, 189 (92.5%) of group A and 342 (98.5%) of group B (n:531) were adequate for evaluation. Nineteen patients (3.4%) were excluded due to incomplete data (8 patients), no follow-up, or referral to another center after diagnosis (11 patients). As grand total from this series it is clear that those patients with early diagnosis (less than 30 days) had a high survival (83.5%), while this number decreased with longer delays (53.3% in 30-60 days and 30.8% in longer than 90 days), but the period of follow-up of Group A (1979-1989) was longer. At the same it was noticed that the survival increased when both periods were compared (1979-89 vs. 1990-2000) from 54.8% to 72.8%, even with no significant changes in the diagnostic delay. This observation sustains the fact that therapeutic advances may disregard the delays. Anyway, delay in diagnosis determines metabolic and nutritional changes, and progression of the disease all of which prevent the use of aggressive and short therapeutic protocols. So, poor response to chemotherapy is more frequent in patients with advanced stages of disease. These patients also present more regularly infectious complications and malnutrition which result in poor tolerance to the treatment.