Disclosed are Computer Aided Diagnosis (CAD) apparatus and method to combine information on sequential image frames and to provide a superior classification result for the ROI in the image frame. The CAD apparatus may include a Region of Interest (ROI) detector configured to detect an ROI from image frames, a categorizer configured to create groups of image frames having successive ROI sections from among the image frames based on a result of the detection, a classifier configured to classify an ROI detected from each of the image frames belonging to the groups, and a result combiner configured to combine classification results for the image frames belonging to each group from the groups and to calculate a group result for the each group.