In this double-blind, standard controlled study we were examining patients with predelirious and delirious symptoms who were treated in the antialcoholic ward PK in Prague ("Apolinář"), In the period of 18. 7. 1984 – 9. 11. 1985 we included 39 patients in the study; 35 finished it. 32 patients were dependent on alcohol, 3 patients depended on other drugs. Two compared groups of patients were formed. In the first group (N = 18) the patients used Heminevrin (Clometiazol) and Tiaprid was used in the other one (N = 17). The average daily dose of heminevrin was 1995,6 mg, that of Tiaprid was 720,7 mg. The groups were comparable as for the age of the patients and clinical diagnoses, somatopsychic damage before administering medicaments when there was not observed any statistically significant difference in the number of symptoms on the twenty-five points scale. The results of observation during 6 days were included in the statistical evaluation. The compared groups did not differ statistically in the degree of improvement of states recorded in individual days during the six-day observation. They did not differ either as for the resulting (overall) improvement of state reached in six days of observation. The highest degree of improvement was recorded in the first two days of observation, when the improvement was statistically significant in comparison with the preceding state, i.e. 24 hours ago. The difference in number and intensity of side symptoms between the two compared groups was not statistically significant. All the side effects resolved while preparations were being administered, except for cephalea in the case of one patient from the Heminevrin group and somnolence in one patient from the Tiaprid group. In the laboratory values there did not occur any pathological values linked with administering Heminevrin or Tiaprid. According to our study, the above mentioned preparations are thus comparable.