The asymmetric unit of the title salt, C10H11N2 (+)·C4H5O4 (-), consists of two independent 5-amino-6-methyl-quinolin-1-ium cations and two 3-carb-oxy-propano-ate anions. Both cations are protonated at the pyridine N atoms and are essentially planar, with maximum deviations of 0.026 (3) and 0.016 (2) Å. In the crystal, the cations and anions are linked via N-H⋯O and O-H⋯O hydrogen bonds, formin...