The article is devoted to the new underwater archaeology research results on mediaeval bridges in Lithuania. Localization of the bridge in Plateliai had been known for a long time thanks to visible timbers on the surface of the lake, during the period of low water. In 1998 Vladas Žulkus, in cooperation with group of divers, defined the detailed localization of the bridge’s sequence, the condition of its relics and some details about the building’s structure also were defined. Further underwater surveys were made after taking up cooperation in a field of underwater researches between the Centre of History of Western Lithuania and Prussia (Institute of Baltic Sea Region History and Archaeology at present) at Klaipėda University and the Institute of Archaeology at the Nicolaus Copernicus University in Toruń. The relics of other late medieval bridges were also discovered in Dubingiai at the Asvejos Lake and in the place called Zarasai in the lake of the same name.