Non-insulin dependent diabetes mellitus is often associated with some complications such as nephropathy, retinopathy and neuropathy. Genes of the renin angiotensin system are potential candidate genes for diabetic complications. We investigated the relationship between angiotensin converting enzyme (ACE) gene polymorphism in type 2 diabetic patients with and without diabetic nephropathy. Seventy five patients (25 type 2 diabetic patients with nephropathy, 50 type 2 diabetic patients without nephropathy) and 37 healthy controls were studied. Gene polymorphism of ACE was determined by PCR (polymerase chain reaction) amplification using allele-spesific primers. The frequencies of ACE DD, ID and II genoypes among the patients with type 2 diabetic patients were found 48%, 42%, 10% whereas in control subjects, 27%, 60%, 13% respectively. Type 2 diabetic patients carrying DD genotype without nephropathy increased 1.77 fold than control subjects (P < 0.05). There is no significant correlation between diabetic nephropathy and ACE gene polymorphism. But we found that ACE DD genotype increased significantly in type 2 diabetic patients compared to control subjects (P <.05).