A process for producing C-methylol imidazoles which comprises reacting imidazole compounds containing an aryl group at the 2-position with formaldehyde in a reaction medium having a pH of at least 7 whereby the formaldehyde adds to the carbon atom of the imidazole ring. The products are either monomethylol imidazoles or dimethlol imidazoles depending upon the starting imidazole compounds. Most of the C-methylol imidazoles thus obtained are new compounds.