Introduction: A rare benign lymphoid proliferative disorder called Castleman’s disease is the most commonly presented as a solitary mass in the mediastinum, although sometimes with sites at the neck, axilla, mesentery, pancreas, pelvis and retroperitoneum. We report a case of Castleman’s disease in the mesorectum. According to the literature, such localization was visualized just in few cases all over the world. Case History: The patient was a 48-year-old man, who complained of lumbar pain. MRI was performed in 2014 on which the formation in the presacral mass of mesorectal fat (size up to 4,9*5,2*4,0 cm) on the level of S2 vertebrae was found, which is considered as a lymph node with the tendency to increase during 3, 5 years (+1cm). Upon admission to the clinic, differential diagnosis with lymphoma and malignant tumor were carried out. According to the colonoscopy, there were no evidence about any malignancies in the bowel. After laparoscopic removing of the mesorectal tumor and histological examination of the specimen immunohistochemistry assay was recommended. Following the analysis, the hyaline-vascular type of Castleman's disease was confirmed. Chemotherapy wasn’t recommended, because of radical surgical treatment. According to the results of monitoring in two years, no data of recurrence were identified. Conclusion: Castleman’s disease should be taken into consideration in the differential diagnosis of lymphoid formations in mesorectum.