The crystal structure of pomiferin, 3-(3,4-dihydroxyphenyl)-5-hydroxy-8,8-dimethyl-6-(3-methylbut-2-enyl)-4H,8H-pyrano[2,3-h]chromen-4-one, C25H24O6, has been determined. The benzopyranone ring system is nearly planar and the dihedral angle between the phenyl ring and the benzopyranone moiety is 40.85(4)deg. The crystal structure is stabilized by a one-dimensional chain of inter- and intramolecular O-HO hydrogen bonds, with O...O distances in the range 2.5546(15)-2.7999(16) A.