Bacterial leaf streak (BLS), caused by the pathogen Xanthomonas campestris pv. Oryzicola, is a major rice disease in tropical and subtropical regions of Asia. Rice proteins responsive to BLS are still not well characterized. We took a proteomics approach to identify the proteins that are up-regulated in rice leaves after infection. Approximately 1,500 protein spots were detected on each 2-D gel after silver-staining; those with increased protein levels were selected for MALDI-TOF-MS analysis. We identified 32 up-regulated proteins that might be involved in disease resistance signal transduction, pathogenesis, and regulation of cell metabolism. By using publicly available microarray data, we determined the mRNA transcripts of 23 proteins expressed in the leaves. Seven genes were analyzed by northern blots, which demonstrated that transcript levels were increased after bacterial infection. Our findings help elucidate the molecular mechanisms underlying BLS and provide a solid foundation for further research on the functions of relevant genes.