The number of avian influenza cases is increasing over the globe from year to year. Only in Europe during the 2020/2021 epidemic season 3.777 outbreaks were recorded. In Serbia first case in wild birds happened in March 2021 in West Bačka District. In Belgrade city area during 2021, twelve suspicious cases of avian influenza in wild birds were recorded. Among analyzed species mute swans dominated. Cloacal and pharyngeal swabs of affected birds were tested for presence of genome of influenza A virus. Positive samples were additionally analyzed in NRL for avian influenza - Veterinary Specialized Institute “Kraljevo”. Out of 12 tested animals, genome of influenza A virus was detected in 5 (41.67%). All positive samples originated from mute swans. Positive birds were found in three locations characterized by proximity of permanent surface waters. Viruses that caused the death in five positive animals belonged to H5N8 subtype and were characterized by high pathogenicity. Based on the data about outbreaks recorded in wild bird populations in surrounding countries during 2020/2021 and in Serbia in last 5 years, occurrence of H5N8 avian influenza virus in mute swans in Belgrade city area are not an unexpected epizootiological situation.