Introduction: Dosage Optimization of gentamicin in hemodialysis is essential to ensure its antibacterial efficacy. The objective of this study was to evaluate the use of gentamicin in hemodialysis patients. Materials and methods: This is a single-center study; a retrospective, descriptive; Observational and analytical study that was carried out at the Pharmacovigilance Department of the University and Hospital Establishment (UHE) of Oran in Algeria, from November 2021 to June 2022. Patient data was collected from the patient information sheet accompanying the sample for the gentamicin assay. The maximum (Cmax) and residual (Cmin) concentrations of gentamicin were measured by immunoenzymatic method. Results: Our study was included 74 patients; which 44 patients were male (59%) and 30 patients were female (41%) with a mean age of 47 years. The gentamicin‘s administration mode of was 4 hours before the dialysis session in 63.9% of patients. The mean doses used were higher in patients who received gentamicin pre-dialysis (group 1), i.e. 2.49 mg/kg versus 1.38 mg/kg for those who received gentamicin post-dialysis (group 2). The target Cmax was reached in all patients treated for bacterial endocarditis in group 1 versus 20% for group 2. In addition, only 28.10% of patients in group 2 had reached the target Cmin after a first session of dialysis, thus delaying the administration of the next dose administration. Conclusion: This study showed that the administration strategy of gentamicin in predialysis has the advantage of reaching the therapeutic target values; however, a clinical evaluation of the effectiveness of this approach in terms of healing speed and time needs to be established.