Plasmatic homocysteine concentration depends mostly on 5,10 methylene tetrahydrofolate reductase (MTHFR) polymorphisms, a key enzyme in folate metabolism. The most common point mutation C677T is associated to cardiovascular and neurological pathologies; its ethnic repartition is quite heterogenic. In the present study, we proposed to describe the genotyarticle pic and allelic frequencies of C677T polymorphism and its influence on plasmatic homocysteine level in a healthy Algerian population. The investigation was turned on 100 apparently healthy voluntary subjects. Homocysteine concentration was determined using an immunoassay by fluorescence polarisation on IMx. Genotypes were determined by RT-PCR (Light cycle 480). Mean homocysteine concentration value was 14,69 +/- 7,30 mu mol/L. 41% of people sample show a moderate hyperhomocysteinemia (> 15 mu mol/L). For the MTHFR C677T, estimated frequency of the allele T in the 100 people sample was about 35,5% with genotypic frequency of 6%. Plasmatic homocysteine is significantly higher in people carrying allele T: (CC vs CT: 11,8 +/- 2,97 mu mol/L vs 15,47 +/- 6,74 mu mol/L, p = 0,0004); (CC vs TT: 11,8 +/- 2,97 mu mol/L vs 30,05 +/- 13,35 mu mol/L, p = 0,01) and (CT vs TT: 15,47 +/- 6,74 mu mol/L vs 30,05 +/- 13,35 mu mol/L, p = 0,021). Our study shows an intermediate allelic frequency that joins the North-South world gradient and a high hyperhomocysteinemia prevalence. C677T polymorphism of MTHFR seems playing a predominant role in the moderate hyperhomocyteinemia. These two observations should be taken into consideration in the evaluation of morbid and/or lethal pathologies predisposition in the Algerian population.