Surname Koustai (Koustai 
) , in all the world, is a rare last name. The family name Koustai is habitual in Cyprus, where it is quite a common surname, Greece, where it is a very rare surname, and the United States, where it is an extremely rare surname. Much less frequently, Koustai is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Koustai | Cyprus, Greece, United States |