An apparatus and method for detecting a 2:2 pull-down sequence, which can accurately detect the 2:2 pull-down sequence is provided. The apparatus includes a main detection unit for calculating a summed absolute difference (SAD) between sequential fields with respect to an input image signal and detecting a 2:2 pull-down image based on the SADs, a sub-detection unit for calculating an absolute change amount between the SADs and detecting the 2:2 pull-down image based on the absolute change amounts, a still image judgment unit for judging whether the input image signal is a still image, and a 2:2 pull-down sequence decision unit for deciding whether the input image signal is the 2:2 pull-down sequence. The apparatus can accurately detect the 2:2 pull-down image by adaptively coping with the changed picture even in the case of much noise.