Type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) are diseases caused by the interaction of genetic and non-genetic factors. Therefore, the aim of our study was to investigate the association between six common genetic polymorphisms and T2DM and MetS in males. A total of 120 T2DM, 75 MetS, and 120 healthy controls (HC) were included in the study. ID, 4a/b, A1166C, (A>G), +35A/C, -21A/T gene polymorphisms were genotyped by PCR or PCR-RFLP techniques. T2DM was diagnosed at an earlier age compared to MetS (54 vs 55 years old, p=0.0003) and the difference was greater in carriers of the G allele (54 vs 56 years old, p=0.0002) or both G and b alleles (54 vs 56, p=0.00016). The AA genotype (O.R.=0.11, p=0.0006) and the presence of both I and A (O.R.=0.39, p=0.0005) alleles revealed to be protective for T2DM. AA and AC genotypes were protective factors for triglyceride (p=0.0002 and p=0.0005, respectively) and HDL cholesterol (p=0.0002 and p=0.0004, respectively) levels in T2DM patients. DD was identified more frequently in hypertensive T2DM patients (O.R.=3.77, p=0.0005) and in those who reported drinking alcohol (p=0.0001) comparing to HC and T2DM patients who did not drink alcohol, respectively. We observed that T2DM patients who reported drinking alcohol had an increased frequency of DD and bb (p<0.0001), or DD and G (p<0.0001) compared to non-drinkers. No gene polymorphisms were associated with MetS.