An automatic detection method to identify bridges over water in high-resolution remote-sensing images is proposed. The input image is first segmented into two water and non-water areas according to homogeneity of the water area. The image is scanned, and the bridge is extracted from the non-water area. The orientation of the bridge is determined using region growing and multiple-direction scanning. The bridge is then accurately outlined from the coarse extraction by extension along its orientation. Experimental results show that the proposed method can automatically detect bridge over water in high-resolution remote-sensing images. Performance evaluation indicates that the proposed method is robust and accurate.