The aim of this study is to investigate the potential diagnostic value of serum matrix metalloprotienase-2 as an early marker of microangiopathy in patients with type-1 diabetes mellitus. The study included 60 children with type-1 diabetes mellitus were classified according to prescence or absence of microalbuminuria and according to receiving or not of ACE-I into 3 groups named normoalbuminuric, microalbuminuric and microalbuminuric receiving ACE-I as treatment. A fourth group of 20 non-diabetic, apparantly healthy, age and sex matched children is considered as the contral group. Results show that there is statistical significant difference in the mean level of serum MMP-2 in the patients with microalbaminuria as compared with the control group as well as the normoalbuminuric group. Also there is significant decrese in MMP-2 serum level after treatment with ACE-I