Yes, so long as there's no sexual tension between them. One of my est friends is a girl I had a crush on for about five years, and asked out multiple times (she had an on-again-off-again crush on me apparently >.>) and amazngly, we're still friends, but I think that's because nothing romantic ever happened between us.
If one is seriously attracted to the other, it can put a strain on things, but doesn't mean that they can't or won't be friends. Although apparently every female friend of mine in highschool and some in middle school had crushes on me at one point or another, which I found annoying, since I had crushes on most of them too, but they were mostly just passing thoughts.