Atsiki (Ατσική) is a municipality on the island of Lemnos, in the Lesbos Prefecture, Greece. It is located in the northern central part of the island and has a land area of 134.672 km², covering about 28.2% of the island's surface. The municipal seat is the town of Atsikí (pop. 918 in 2000 census). Its next largest town is Ágios Dimítrios (733). The municipality's total population is 3,225 inhabitants.
