Cognomen Kosciow (Kosciow 
) , all over the world, is a rare family name. The cognomen Kosciow is habitual in Poland, where it is a rare surname, Germany, where it is a very rare surname, and Brazil. Measured by absolute frequency, the name is most common in Poland, Brazil, and the United States. Likewise, Kosciow is the forename as well as the last name.