Países

Países
 

Does 'país' keep the accent in the plural?
Is the correct word 'países?

Many thanks in advance.

Yes, the accent mark is still needed in the plural.

Thanks so much, Rusty.

The accent there is to break the diphthong; "i" is a "weak" vowel that becomes "strong" with the accent, so it becomes a syllable by itself.

pa·ís
pa·í·ses