No, you just need a bachelors degree and you need to take the GMAT. I know numerous MBA's, and they have all different kinds degrees. Unlike pre-dents and pre-meds, an MBA doesn't really have any pre-reqs. However, top MBA schools usually require you to have about 3-5 years of work experience, and three letters of rec from your employer. It is very rare to get accepted into a top MBA program without work experience.