Provided are a method for producing a 5-hydroxy-1H-imidazole-4-carboxamide•3/4 hydrate, including reacting an acidic salt of 5-hydroxy-1H-imidazole-4-carboxamide or a hydrate thereof with a base selected from the group consisting of a phosphate and an amino acid in the presence of an acidic solvent to obtain a 5-hydroxy-1H-imidazole-4-carboxamide•3/4 hydrate； and a 5-hydroxy-1H-imidazole-4-carboxamide•3/4 hydrate obtained by the production method.
