The Homocysteine (Hcy) is a non-proteinogenic sulfur amino acid that results from methionine demethylation. Nutritional deficiency or genetic abnormalities of Hcy metabolism cofactors leads to hyperhomocysteinemia (hHcy) which is considered as an independent risk factor in the occurrence of several pathologies. The aim of this study is to determine the prevalence of hHcy in a general population in order to compare the relationship of Hcy betweenage, sex and its association with different pathologies in patients. The study involved a population of 140 patients, according to the age there are 131 adults and 9 children, and according to the gender there are 87 female patients and 53 male patients, recruited from several services. Then, the sampling was carried out at the medical biology department at the Ain Taya University Hospital (near Algiers). The patients' plasma Hcy level was measured using the principle of competitive immunodosage and enzyme dosage of Hcy. In Conclusion, our results state that the rate of total homocysteine (tHcy) increased with age, higher in men than in women and that this increase is due to metabolic disturbances associatedwith different pathological conditions. It can be said that an increase in tHcy in excess of 15 µmol/l is considered as an independent risk factor for various pathologies, such as venous thromboembolic diseases, stroke or renal failure.