The aim of this molecular study was to evaluate a possible association between hyperhomocysteinemia and the different genotypes of the C677T polymorphism of MTHFR gene, based on clinical and biochemical data, in pathological population, residing in Aurès region (Northeast Algeria). The present study included 14 young patients of rare age group, all patients were in the chronic phase of myocardial infarction (MI). Competitive immunoassay was used for the determination of vitamins (B9 and B12) and total homocysteine and the identification of MTHFR polymorphism was determined by Real-Time Polymerase Chain Reaction - Fluorescence Resonance Energy Transfer (Real-Time PCR -FRET). Results showed a non-significant association of moderate hyperhomocysteinemia (Hhcy) with the different genotypes of the C677T polymorphism (P = 0.117). However, a decrease in folate and B12 was recorded with moderate Hhcy for (TT) genotype but remains non-significant (P = 0.901, P = 0.304 respectively). No significant differences in the clinical and demographic patient characteristics according to the different genotypes of MTHFR C677T plymorphism were revealed. Same results were observed for the majority of biochemical variables. This is probably related in part to coronary patients who are in the chronic stage of the disease. Our study supports the hypothesis indicating that the polymorphism C677T MTHFR could be considered an important risk factor for MI, in the presence of moderate hyperhomocysteinemia. We suggest a strategy for the biological exploration of moderate or intermediate Hhcy, for informing the general public in our region (Aurès) and country face the risk of the evolution of this symptomatology.