Masahito YamazakiDepartment of Physics, University of Tokyo, Hongo 7-3-1, Tokyo, 113-0033, Japan E-mail: yamazaki@hep-th.phys.s.u-tokyo.ac.jp Abstract: We propose a new method to find gravity duals to a large class of threedimensional Chern-Simons-matter theories, using techniques from dimer models. The gravity dual is given by M-theory on AdS 4 × Y 7 , where Y 7 is an arbitrary seven-dimensional toric Sasaki-Einstein manifold. The cone of Y 7 is a toric Calabi-Yau 4-fold, which coincides with a branch of the vacuum moduli space of Chern-Simons-matter theories.