Area: 42,08 km2
Coastline length: 37 km
Island capital and its population: Agios Efstratios (371)
Administrative structure: Region of North Aegean, Prefecture of Lesvos, Province of Limnos, Community of Agios Efstratios
Archaeological sites and monuments: Ruins of prehistoric settlement at Alonitsi, ruins of the ancient city of the island at the hill of Agios Minas, ruins of ancient cemetary at Evraiki
Natural monuments: The island has been included in the European network "NATURA 2000" as a Site of Community Importance (SCI) and has been declared an Important Bird Area of Greece.