The title compound, 1-methylimidazolium D-tartrate, C4H7N2+.C4H5O6- consists of a tightly interwoven tartrate network that is hydrogen bonded to the imidazolium cations. There is a broad range of hydrogen-bond interactions within this structure. The interactions between the anions and cations are believed to influence the alignment of the cations and thereby contribute to the nonlinear optical activity of the salt.