Surname Piiroja (Piiroja 
) , throughout the world, is a rare family name. The cognomen Piiroja is characteristic of Estonia, where it is quite a rare surname, Finland, where it is a very rare surname, and Peru. Not in comparison with a country's population, this name is the most popular in Estonia, Peru, and Brazil.
| VARIANT | COUNTRY |
|---|---|
| Piiroja | Estonia, Peru, Chile, Finland, Brazil |
| eduard piiroja Estonian chemist (1931-1996), EE (b. 1931) |
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