49% of patients who abused alcohol were detected among 119 persons with O. felineus infection in the focus of the infection in the Komi-Permiak Autonomous Okrug by screening questionnaire test. The abuse of alcohol in the given focus was shown to be associated with consumption of low-salt fish mostly by men. Alcoholism promotes failure to keep medical recommendations on the prevention of Opisthorchis infection and reduced motivation of opisthorchiasis treatment, and due to re- and superinvasion it decreases the efficiency of chemotherapy. Comparing the results of praziquantel treatment a month or a year after, treatment efficiency among those abusing alcohol was shown to decrease from 88% to 68%.