Could somone please explain what is to be assumed at the end of K-PAX? It was such a good movie, but was the ending supposed to be so ambiguous?

You’re in luck. We just discussed this movie a little while ago.

Of coarse it was supposed to be that ambiguous. I love this movie for that reason. Most movies they make these days spoon feed an audience every little plot point, and idea. without leaveing room for interpretation. K-PAX didn’t do that. Which is why I think it didn’t make more money than it did. At the end you are made to make your own decision about what really happened. People don’t usually find this comfortable. If they aren’t told for sure what is going on by the end of the film they feel cheated or like they missed something. I think that the writer and director made this film leave a lot of questions to give the idea of the movie more force. throughout the film you want to know the truth about Prot when the reality is that the truth is simply a matter of what you believe. IMHO, anyway.

I agree with almost everything you say, in principle. But K-Pax is not a good example of an ambiguous movie, and it is in fact a lot less ambiguous than you may think–just highly pretentious. See the thread Yosemitebabe linked, in which I argue why the film is not really ambiguous. In that same thread I recommended Donnie Darko as infinitely superior. It is a very intelligent, interesting, and abstruse film that will suggest about 6 different interpretations ranging from the divine to the accidental. There are no explosions in this very cerebral film, and Toby Maguire’s performance is his best that I have seen. Judging from your post, I think you will enjoy this film quite a bit.

But K-Pax on closer analysis was a hole in the water, even though I thought what it was trying to do was worthy–too bad about the uninspired execution. It tried to be One Few Over the Cuckoo’s Nest and Starman combined, and was neither. Nor did it do justice to the themes it lightly touched upon in trying to dazzle and awe the audience with its cleverness. I alos find that the film speaks down to its audience, which is never a good idea. This is not good science fiction, although I do admire the more intellectual approach (in spite of the pedestrian layman execution).