BACKGROUND Retroperitoneal fibrosis (RPF) is a rare disease with a poor prognosis characterized by systemic inflammation and fibroinflammatory tissue. Idiopathic RPF (IRPF) accounts for approximately two-thirds of RPF cases. METHODS A 56-year-old female patient with abdominal distension was admitted to Changxing Hospital. Laboratory tests revealed mild anemia and elevated CA125, while IgG4 and autoantibodies were within the normal ranges. Computed tomography (CT) revealed a gallbladder-occupying lesion, pancreatic cyst and retroperitoneal mass, which may have contributed to bilateral ureteral compression and hydronephrosis. The initial diagnosis was gallbladder carcinoma with lymph node metastasis. Then, abdominal adhesiolysis, cholecystectomy and partial hepatectomy were performed. Histologically, there were fibrosis and inflammation in the retroperitoneal tissue without any malignant cells in the retroperitoneal or gallbladder tissue. Finally, we confirmed the diagnosis of idiopathic retroperitoneal fibrosis, chronic cholecystitis and pancreatic cyst. The patient recovered well following the CT scan, in which dilatation of the bile duct was reduced, and effusion of the bilateral upper ureter was no longer significant. CONCLUSIONS This atypical case illustrates that RPF can be combined with other biliary tract diseases. The coexistence of other diseases conceals the symptoms of RPF, which increases the difficulty of image identification. A high degree of suspicion is necessary for routine clinical work. As more cases are reported, further advances in the diagnosis and treatment of RPF can be expected.