title-ing a book with the same title of another book (derp :p)

OK finally finished the title!

So I have a questio, well I'm writing a book, and the title of my book is the same of another's book which had a lot of success.

so my question is is the title really important even if it is almost the same title as the book that had a load of success because the story is not really the same and obviously if it was I would probably get sued or something like that so... answers please :)

(I now realize that I said 'title' many times. Oops) :p