Last name Gaztanaga (Gaztanaga 
) , in the entire world, is a very rare cognomen. The last name Gaztanaga is habitual in Spain, where it is a very rare surname, Colombia, and Ecuador. In absolute terms, it is commonest in Spain, Colombia, and the United States. Much less frequently, Gaztanaga is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Gaztanaga | Colombia, Ecuador, United States, France, Spain |