Urinary levels of beta 2 microglobulin (beta 2 MG) and dipeptidipeptidse IV (DPP IV) were measured in 30 insulin dependent diabetes mellitus children aged 5 to 18 years. The control group consisted of 30 healthy children. Metabolic control (HbA1C) and the duration of diabetes were directly correlated with the levels of beta 2 MG and DPP IV. Beta 2 MG urinary levels were significantly increased in the diabetic group (MV = 0.340 +/- 0.076 mg/l) as compared with the controls (MV = 0.081 +/- 0.012 mg/l, p < 0.05). These values correlated only with the duration of diabetes and not with the HbA1C. DPP IV excretion was elevated in all diabetic patients (MV = 6.40 +/- 0.83 j/l). Significant correlations were not identified between urinary DPPIV excretion and the duration of diabetes and metabolic control.