Who is the protagonist and antagonist in "The Tell-Tale Heart" by Edgar Allen Poe?

This is actually an interesting question, because the
narrator of the poem--who we are used to being the good guy--is also the man who commits
murder.  He would like us to think that he is the good guy--a blameless, completely sane
person who did only what anyone else would have done in his situation.  He would have us
believe that he is the brave protagonist, and the old man with the evil eye is the
antagonist; after all, that eye certainly did antagonize him. Looked at in that way, the
narrator is the protagonist and the old man (or his eye, even) is the
antagonist.

The protagonist to a story usually is the
character around whom the action is centered; in this case, that is the murderous
narrator.  However, usually the audience is supposed to be able to relate to the
protagonist, and traditionally, he is thought of as a hero. I don't relate to a clearly
insane murderer, nor do I think he is a hero, so that is where this question becomes
tricky--yes, the narrator is the protagonist, but we certainly don't like him or relate
to him.  I also don't think that the old man (or his eye) were classic antagonist; he
isn't actively contending against the narrator.  He isn't going out of his way to create
conflict and chaos in the narrator's life--he simply exists.  So the old man is not your
classic antagonist either.

This poem definitely tests the
boundaries of our definitions of protagonist and antagonist; that's just one more reason
it is so interesting.  I hope that those thoughts helped; good
luck!