To provide a method of manufacturing a bend-shaped pipe which is small in thickness difference between the inside and the outside of a bend portion.

The method includes a process where an uneven thickness pipe 1A which is gradually thicker in a part of a circumferential direction in a cross section is prepared and a process where this uneven thickness pipe 1 is made into the bend-shaped pipe 1A by performing bending work taking a thick-walled side as the outside and a thin-walled side as the inside. The process for preparing the uneven thickness pipe 1A comprises, for example, a process where a uniform thickness pipe 1B having a uniform thickness on the entire circumference is prepared and a process where the uneven thickness pipe 1A a part of which is made thicker gradually in the circumferential direction by applying plastic working to the uniform thickness pipe 1B.