To clarify the effect of a phytochemical, methyl gallate (MG) on a heavy metal (cadmium)-induced renal toxicity, cytotoxicity and the change of heme oxygenase-1 (HO-1) gene expression was studied using cultured mouse renal glomerular mesangial cells (MMC). By employing RT-PCR and Western blotting analysis, we have examined the HO-1 induction in MMCs that were treated with $Cd^{2+}$ and/or MG. Using MTT assay we have also examined the cytoprotective effect of HO-1 induction against the cytotoxicity caused by toxic dose of $Cd^{2+}$. In MMCs exposed to $Cd^{2+}$ and MG, expression of HO-1 (mRNA and protein) was increased in a concentration- and time-dependent manner. The increments of HO-1 mRNA and protein expressions by $Cd^{2+}$ and MG were inhibited by the treatment of the cells with actinomycin D, an inhibitor of transcription. The decreased viability of the cells by $Cd^{2+}$ was partially recovered by the treatment of MG and this recovery by the MG was reduced by the treatment of zinc protoporphyrin IX (a HO-1 inhibitor). From these results, methyl gallate might have cytoprotective effect on $Cd^{2+}$-induced cytotoxicity that is related with heme oxygenase-1 induction.