The title salt, C(14)H(31)N(2) (+)·C(15)H(9)O(7) (-), was obtained in the reaction of quercetin with n-butyl-amine in a mixture of acetone and hexane. The crystal structure determination shows that the quercetin donates one of its phenol H atoms to the N-butyl-4-butyl-imino-2-methyl-pentan-2-amine mol-ecule. The crystal structure of the salt is stabilized by intramolecular (N-H⋯N for the cation and O-H⋯O for the anion) and intermolecular hydrogen bonding (N-H⋯O between cation-anion pairs and O-H⋯O between anions). Quercetin molecules form dimers connected into a two-dimensional network. The dihedral angle between the quercetin ring systems is 19.61 (8)°.