is homosexual a derogatory term?

Not as such. But there are certainly people who use it as such. I've noticed that some of those people tend to say "he's a homosexual" instead of "he's homosexual".

Just compare the word 'gay'. Someone coming out to you can say "I'm gay" and there is nothing derogatory about that. Or I can tell you that my friends are a gay couple, and that's fine too. But when you hear some guy say "that Andy dude is SO gay!" he probably doesn't mean it in a good way.

It is the correct term for people who are sexually attracted to the same sex. If they call you a homo then I think that is derogatory.

'Is homosexual a derogatory term?'

No, in fact it's the appropriate term.

No - it's just the correct term for someone who is gay.

Well..... sort of. It's a little clinical. Think about how many people refer to you as a "Heterosexual".

Yeah, and so is black!

not if you emphasize the "Homo" part.