The chemical preparation and crystal structure of styphnic acid and naphthalene-1,4-diol (1 : 1) (I) have been reported. The compound crystallizes in the orthorhombic system in space group Pnma and cell parameters a = 6.6712(2), b = 16.8267(7), c = 13.6450(5) angstrom and V = 1531.71(10) angstrom(3), and Z = 4. Crystal structure has been determined and refined to R = 0.0576. The crystal structure of I, the asymmetric unit, contains C6H2N3O7, C10H7O, and it is a half portion of both styphnic acid and naphthalene-1,4-diol. The O1-H1 center dot center dot center dot O2 intramolecular hydrogen bond was found between the O-H and a nitro group in the styphnic acid unit.