Cognomen Isaias Gustavo (Isaias Gustavo 
) , all around the world, is an extremely rare last name. The family name Isaias Gustavo is habitual in Latin America and the Caribbean, particularly Chile, where it is a very rare surname. More frequently, Isaias Gustavo is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Isaias Gustavo | Mexico, Peru, Ecuador, Chile, Costa Rica |