Provided is a method for producing 5-hydroxy-1H-imidazole-4-carboxamide·3/4 hydrate, including: reacting 2-aminomalonamide with a compound represented by the following formula [1] in the presence of a carboxylic acid to obtain 5-hydroxy-1H-imidazole-4-carboxamide: wherein, in formula [1], each R independently represents a C 1-3 alkyl group reacting the resulting 5-hydroxy-1H-imidazole-4-carboxamide with an acidic compound to obtain a 5-hydroxy-1H-imidazole-4-carboxamide acid salt or a hydrate thereof and reacting the resulting 5-hydroxy-1H-imidazole-4-carboxamide acid salt or hydrate thereof with a salt in the presence of an acidic solvent to obtain the 5-hydroxy-1H-imidazole-4-carboxamide·3/4 hydrate.
