Lake Petén Itzá (Lago Petén Itzá, Spanish pronunciation: [ˈlaɣo peˈten iˈtsa]) is a lake in the northern Petén Department in Guatemala. It is the third largest lake in Guatemala, after Lake Izabal and Lake Atitlán. It is located around 16°59′0″N 89°48′0″W / 16.98333°N 89.80000°W. It has an area of 99 km (38 mi), and is some 32 km (20 mi) long and 5 km (3.1 mi) wide. Its maximum depth is 160 m (520 ft). The lake area presents high levels of migration, due to the existence of natural resources such as wood, chewing gum, oil, and agricultural and pasture activities. Because of its archaeological richness, around 150,000 tourists pass through this region yearly. The city of Flores, the capital of the Petén Department, lies on an island near its southern shore.
Several streams flow into Lake Petén Itzá, but it has no surface outflow. Although it loses water mostly by evaporation, it is not a salt lake.