To improve video quality and coding efficiency, H.264/AVC [1] has adopted several newer coding tools such as a 4?4 integer DCT and a method for calculating half pixels than the previous standards. However, these tools require additional work to transcode video content for pre-coded in the previous standards to H.264/AVC in the DCT domain. In this paper, we propose, as far as we know, the first half-pixel correction method for MPEG-2 to H.264 transcoding in the DCT domain. In the proposed method, an MPEG-2 block is added to the correction block obtained from the difference between half-pixel values of the two standards using a DCT reference frame. Experimental results show that the proposed method achieves better quality than the pixel based transcoding method.