Objective. To assess the incidence of influenza in the epidemic season 2018/19 and to analyze severe cases that required extracorporeal membrane oxygenation (ECMO). Patients and methods. A total of 5,939 patients diagnosed with influenza and acute respiratory viral infections (ARVIs) were treated in S.P.Botkin Clinical Hospital for Infectious Diseases of Saint Petersburg in 2018–2019. The highest incidence was observed in the late January – early February. We tested 2,527 patients (42,5%) using polymerase chain reaction (PCR); of them, 1,014 patients (40,1%) were PCR positive for influenza. The vast majority of them (99.3%) were infected with influenza A. One hundred and thirty patients required treatment in the intensive care unit (ICU) (2.2%; 95% CI 1.8%; 2.6%). Results. Severe forms of the disease were primarily caused by influenza H1N1. Respiratory failure was treated by oxygen therapy in 81.7% of patients, artificial ventilation in 15.3% of patients, and ECMO in 3 patients (2.9%; 95% CI 0.6%; 8.5%) Conclusion. Approximately 0.01% to 1.6% of patients admitted to a hospital for infectious diseases with influenza or ARVI during the epidemic season require ECMO.