The paper presents the results of a survey of 35 patients with liver diseases of various etiologies hospitalized in Gastroenterology Department of Republic Clinical Hospital in Kazan. The patients were distributed according to etiology: liver cirrhosis — 28 (80%), acute hepatitis — 5 (14.3%), after liver transplantation — 2 (5.7%). The patients underwent a complete clinical examination, and psychometric tests were additionally used to assess the stage of hepatic encephalopathy. Blood ammonium level was determined in all patients using the PocketChem BA PA-4140 blood ammonia meter. Connect-the-Numbers Test revealed encephalopathy in 97.1% of patients with liver diseases, while latent hepatic encephalopathy was observed in 47% cases. According to the West-Haven criteria, hepatic encephalopathy was diagnosed in 80% patients. Hyperammonemia was determined in 80% of patients with liver diseases. There was some relationship between the ammonium level and the stage of hepatic encephalopathy.