Family name Исага (Yzaga 
, Исага) , in the world, is a rare last name. The surname Исага is characteristic of Latin America and the Caribbean, particularly Peru, where it is a rare surname, Venezuela, where it is a very rare surname, and Chile, where it is an extremely rare surname. Not in comparison with a country's population, it most frequently occurs in Peru, Venezuela, and Spain. Very seldom, Исага is the forename as well as the last name.