The association of sclerosing cholangitis, retroperitoneal fibrosis, and Riedel's thyroiditis has been reported twice before, and on both occasions the authors successfully used steroids to control the fibrotic process. A further case of fibrosis with this triad of organ involvement in which a combination of surgery and steroid treatment has arrested disease progression is described. This suggests an inappropriate immune response in this type of fibrotic overlap syndrome.