The results of the clinical trial testing the efficacy of a new anti-influenza drug Triazavirin are presented in this work. The data of the trial were gathered during the 2010 influenza season. The treatment with oral Triazavirin significantly reduced the duration of the main clinical symptoms of influenza (intoxication, fever, respiratory symptoms), decreased the incidence of the influenza-related complications and the use of symptomatic drugs. The re-isolation rate of the influenza A and B viruses was significantly lower in the patients who were using Triazavirin. The analysis of the clinical data showed that the optimal prescribed dosage was 250 mg 3 times a day