Video transmission over error-prone channels often suffers from inevitable transmission errors, which necessitates proper error concealment (EC) for acceptable image quality. Furthermore, the region of interest (ROI) in images usually draws much attention, and so the EC of the ROI receives special treatment during encoding and decoding. We explore a data hiding-based scheme to effectively improve the EC of the ROI in the case of erasures of large continuous regions, which becomes impractical for conventional EC methods. At the encoder side, motion vectors of the ROI are adaptively embedded in the background based on original quantized coefficients of background macroblocks. Considering the limited embedding capacity of the background, we further propose to assign priorities to each ROI macroblock based on a predefined metric of error propagation. Our scheme is applied with the state-of-the-art H.264/AVC standard in a packet loss scenario, and better video quality can be obtained. Experimental results show that the scheme can improve the EC of the ROI significantly without much loss of coding efficiency.