A process for purifying methyl methacrylate. The method comprises: (a) feeding a product mixture comprising methyl methacrylate, methanol, water and oligomers of methyl methacrylate to a divided section of a distillation column comprising a dividing wall; (b) removing an overhead stream and a bottoms stream from the distillation column, and removing a middle side draw stream from the distillation column; wherein the crude product enters the dividing wall distillation column in a divided section on an opposing side of the dividing wall from the middle side draw stream; and (c) removing an upper side draw stream from a point above the dividing wall and below the top of the distillation column, separating a portion of water from the upper side draw stream to produce a dewatered upper side draw stream and returning the dewatered upper side draw stream to the distillation column.