Objective:To investigate the clinical characteristics and treatment analysis of unicentric retroperitoneal Castleman's dis-ease (CD) and to improve its levels of diagnosis and treatment. Methods:The clinical data of 18 patients with unicentric retroperitone-al CD were retrospectively reviewed from January 2002 to December 2016. We analyzed the demographic characteristics, clinical fea-tures, histological diagnosis, treatment, and prognostic characteristics of these patients. Results:The patients comprised 4 males and 14 females with a median age of 44.1 years old (ranging from 24 years old to 70 years old). The tumor was located in the kidney in one case, while it was located in the adrenal region in eight cases. In the other cases, the tumor was in the retroperitoneal region. Seven patients had a clinical atypical abdominal pain, and one patient had moderate anemia. All patients underwent surgical resection. The mean operation time was 153.3 min with a range of 60 min to 260 min. The mean blood loss was 447.2 mL (ranging from 10 mL to 3000 mL). Two cases had blood transfusion after operation, and one had urinary fistula complication. CD was confirmed by histopathol-ogy. Hyaline vascular type of CD was observed in 16 cases, and mixed type of CD was observed in 2 cases. The median follow-up was 25 months. One patient had tumor recurrence after 2 years of operation and died. Other patients remained alive without recurrence. Conclusion:Unicentric retroperitoneal CD is a rare disease that is often misdiagnosed because of the absence of specific clinical mani-festations. The final diagnosis depends on the results of a pathologic examination. Complete surgical resection offers a favorable result for unicentric retroperitoneal CD.