Cognomen Koroso (Koroso 
) , worldwide, is quite a rare family name. The cognomen Koroso is characteristic of Tanzania, where it is quite a rare surname, Kenya, where it is a rare surname, and Spain, where it is a very rare surname. In absolute terms, it is the most numerous in Sub-Saharan Africa, particularly Tanzania, Kenya, and Nigeria. Also, Koroso is the forename as well as the last name.