To provide a cleaning composition for molded plastic resin tableware capable of completely cleaning the stain such as blot on the surface of the plastic resin without losing the luster of the resin and provide a method for the cleaning of the tableware.

The cleaning composition for a molded plastic resin tableware is composed of an inorganic alkaline aqueous solution containing 0.05-30 wt.% inorganic alkaline agent and an aqueous solution of an organic acid containing 0.01-30 wt.% organic acid. The stain such as blot on the surface of a plastic tableware can be removed without losing the luster of the surface of the tableware by immersing the tableware in the inorganic alkaline aqueous solution, rinsing with water, immersing in the aqueous solution of the organic acid and again rinsing the tableware with water.