Diabetic nephropathy (DN) is one of the severe complications of Type-2 diabetes mellitus (T2DM) and a major cause of end-stage renal disease in these patients. Results from published studies on the relationship between angiotensin-converting enzyme (ACE) insertion/ deletion (I/D) gene polymorphism and patients with DN are still conflicting. We compared the clinical characteristics and the genotype frequencies of ACE polymorphism in 130 T2DM Moroccan patients with DN and 85 T2DM Moroccan patients without DN (controls) using specific primers in a polymerase chain reaction. The degenerative complications of diabetes were significantly higher in the group with nephropathy. The distribution of the I/D genotypes was in Hardy-Weinberg equilibrium. The D allele was the most frequent allele in the Moroccan population in both groups studied (P = 0.68), however, there was no significant difference between the genotypes in T2DM patients with or without DN (P = 0.78). The ACE gene I/D polymorphism was not associated with an increased risk of DN in the Moroccan population.