In this letter, we present a simple but efficient intra prediction mode decision for H.264/AVC. Based on our investigation, the DC mode appears to be the superior prediction mode among the various candidates. We propose an intra-mode decision algorithm where the DC mode is chosen as a candidate for the best prediction mode. By experimental results, on average, the proposed algorithm significantly saves 81.905% of the entire encoding time compared to the H.264 reference software; besides, it reduces negligible peak signal-to-noise ratio (PSNR) values and slightly increases bitrates.