They are five: A, E I, O, U.

As the others said there are 5 vowels in the spanish language and they sound like this: a(ah) e(eh) i(ee) o(uh) u(oo), only the vowels aren't stress in spanish: á é í ó ú all the other letters can not have accents.

there are five vowels : a - e - i - o - u Good luck with spanish

son 5, pero pueden estar juntas dos o tres y formar diptongos o tridiptongos, en realidad se pronuncian todas

I missed a word in the latest answer i meant "stress less". Sorry.