A method for producing an endoscope flexible tube excellent in operability, heat resistance and chemical resistance is provided. There is prepared a flexible tube assembly (64) including a spiral tube formed by spirally winding a metal strip and a cylindrical mesh sleeve, covering the spiral tube, formed by knitting metal wires； the flexible tube assembly (64) is covered with an outer coat (68) so as to be constant in thickness from one end toward the other end of the flexible tube assembly (64) by using an extrusion molding machine (138) wherein the outer coat (68) has a lower layer formed of a thermoplastic polyurethane elastomer and an upper layer formed of a thermoplastic polyester elastomer. The outer coat (68) covers the flexible tube assembly (64) while the melt viscosity ratio (thermoplastic polyurethane elastomer/thermoplastic polyester elastomer； with reference to the exit temperature of the extrusion molding machine) between the thermoplastic polyurethane elastomer and the thermoplastic polyester elastomer is being set to fall within a range from 1 to 35, and the thicknesses of the upper layer and the lower layer are being gradually varied from one end toward the other end.
