Serum levels of advanced glycation end products (s-AGEs) were investigated in children with poorly metabolically controlled diabetes to determine whether they may be correlated with HbA1c, fructosamine, glycaemia, albumin excretion rate, duration of diabetes and age. In this study, 17 children with Type 1 diabetes mellitus (age range 9 to 18 yr) and 8 healthy children (age range 7 to 17 yr) served as subjects. S-AGEs were found to be increased in poorly metabolically controlled children with diabetes (HbA1c>9%). A significant correlation (r=0.65;p<0.01) was found between s-AGEs and HbA1c in the group of diabetic children. In poorly metabolically controlled children with diabetes of pre-pubertal and pubertal age, the level of s-AGEs should be monitored as the risk of microvascular complications may be already present at this early stage of life.