An effective method for isolation of influenza virus from the nasopharyngeal specimens of patients is described consisting of interruption of the virus reproduction cycle in chorioallantoic membranes of chick embryos (CECAM) at early stages of development of the infection followed by inoculation of infected CECAM homogenate into a fresh homologous medium. The new method of virus isolation is superior to the conventional one by a higher isolation rate, economy of material and time saving which is important for identification of influenza outbreaks.