We previously reported that methylmercury induces brain-specific upregulation of a chemokine gene, the CCL4 gene. In this study, we investigated the changes in gene expression levels of all chemokines in various tissues (cerebellum, cerebrum, kidney, liver, and spleen) of methylmercury-treated mice. We found that methylmercury induced upregulation of the CCL4 gene and the CCL3 gene, in a brain-specific manner. This finding suggests that upregulation of these two chemokine genes mediates selective damage by methylmercury in the central nervous system.