The mercuration of methyl red and methyl orange with mercuric acetate, mercuric chloride, mer¬curic oxide, and mercuric iodide gave different mercurated products. Mercuration was found to occur predominantly in the orthoposition. The structure of these componuds were confirmed by IR, NMR, Mass spectra and micro Chemical analysis. The regiospecifity of these reactions suggest that the mercury atom is directed into an ortho position by the coordination to the azo nitrogen .