The intrinsic reaction coordinate pathway for the gas-phase, base-catalyzed hydrolysis of methyl formate has been determined using ab initio molecular orbital calculations at the MP2/6-31+G(d)//RHF/6-31+G(d) level of theory. Intermediate structures along the reaction pathway include an ion-dipole complex between the reactants, two conformationally distinct tetrahedral intermediates, and a hydrogen-bonded complex between the products.