Disclosed is an apparatus and method for compensating for estimated motion vectors by deciding whether a pattern image exists in target blocks for motion estimation. A motion estimation part compares a current block of a current frame/field to a search area established in a previous frame/field, calculates plural motion estimation error values, and estimates a temporary motion vector of the current block based on the plural motion estimation error values. A pattern decision part analyzes the calculated motion estimation error values, and decides that the current block is a pattern image. A motion compensation part produces a compensation motion vector of the current block by use of the plural motion estimation error values if the current block is decided as the pattern image. A motion vector selection part selects a final motion vector based on a result of the pattern decision part.