We propose a fast and simple shot-cut detection algorithm, which directly operates in a compressed domain and is suitable for real-time implementation. The proposed algorithm exploits the existing MPEG techniques by examining the prediction status for each macro-block inside the B and P frames. As a result, locating both abrupt and dissolved shot cuts is operated by a sequence of comparison tests; thus, no feature extraction or histogram differentiation is needed. Although the description of the algorithm is primarily based on MPEG-1 and MPEG-2 streams, the scheme can be readily extended to other video compression standards such as MPEG-4 and H.264 by following the principle on monitoring: (1) balance between forward prediction and backward prediction; and (2) boundaries among the P, B, and I frames. Extensive experiments illustrate that the proposed algorithm outperforms similar existing algorithms, providing a useful technique for fast and online video content processing.