Aim of the study: Assessment of the CYP2D6 isoenzyme activity: in alcohol dependent patients based on sparteine oxidation rate. Material and methods: Oxidation rate of sparteine was examined in a group of 102 patients with diagnosis of alcohol dependence and has been compared with a control group consisting of 160 volunteers. The assessment of oxidation rate of sparteine was carried out during the withdrawal syndrome. Results: Among the patients, 97.1% were classified as extensive metabolisers (phenotype EM) and 2.9% as poor metabolisers (phenotpe PM). There was no statistically significant difference in proportions of EM's and PM's subgroups between patients and the controls. Signiicant differences were observed in the distributions of sparteine metabolic oxidation ratio (MR); a higher oxidation rate was noted in the studied group, in comparison with the controls. The length of the dependence period does not have an (effect on the MR values. Conclusion: Patients who are in the midst of the alcohol withdrawal syndrome do not have a defected process of oxidation in the presence of CYP2D6 and as a result of this parameter; there is no need to reduce the dosage of drugs metabolized by this enzyme.