A wide var iety of chemical processes have been used for the synthesis of amino acids from prebiot ic molecular precursors under plausible pr imi t ive Earth conditions (M i l l e r , 1982). The prebiot ic formation of a l l protein-type amino acids has been demonstrated except for three amino acids: h is t id ine , lys ine, and arginine (Weber and Mi l l e r , 1981). As a continuation of our work on the prebiot ic synthesis of imidazole, 2-methylimidazole, and 4-methylimidazole (Or6 et a l . , 1984), th is paper reports the prebiot ic synthesis of other imidazoles (l~-4-acetaldehyde, Im-4-glycol, and Im-4-ethanol), which are among the intermediate products in the proposed prebiot ic synthet ic pathway of h is t id ine.