Dear jossie87,
You need to give a complete and accurate job history on your application. Obviously, you want to choose your words carefully in noting your reason for leaving, but you do want to be honest. Depending on the reason for termination, there might be consequences for future opportunities. However, I can't think of a reason that would necessarily result in a rejection from business school. If your termination is for something illegal or is that serious in nature, then it could be a problem, but it would greatly depend on the circumstances and what you are doing/have done to rectify the situation. Schools do background checks on occasion, so they can determine if you have left a job off of your application or if you put down misinformation (which would be fraud). If you do not disclose a full and accurate history, then that would be automatic grounds for rejection as that would be seen as a fraudulent application.
Good luck,
Lisa