An apparatus and method for handover in a mobile communication system enables a Mobile Station (MS) to perform a normal handover without performing an unnecessary handover. A Base Station (BS) apparatus capable of preventing an unnecessary handover includes a handover manager. The handover manager receives handover information, including information about at least one cell through which an MS has passed, from a neighbor cell to determine whether the MS has performed an unnecessary handover. If it is determined that the MS has performed an unnecessary handover, the handover manager notifies the occurrence of the unnecessary handover by the MS to the neighbor cell.