Schwannoma is a benign nervous tumor arising swhan cells with a difficult preoperative diagnosis. The retroperitoneal localization is exceptional and its occurrence during Von Recklinghausen’s disease is rare. Von Recklinghausen’s disease is an evolutionary pathology characterized by the involvement and impairment of several organs deriving from the neural crest. Some complications can be seen, but the most serious complication is the degeneration of neurofibromas. We report the case of a 28 years old patient, who consulted for left low back pain, CT scan has revealed a cystic mass behind the left hepatic lobe, and MRI was in favor of a remanied bilary cyst. a laparoscopy for diagnostic and therapeutic purposes has been proposed, and has objective a retroperitoneal cystic mass, that doeas not depend on the liver or the pancreas, pathologic examination after total excision of the tumor, conclude with a benign schwannoma, subsequently the diagnosis of the associated Von Recklinghausen disease was established before the combination of diagnostic criteria. Complete surgical excision of the tumor the reference treatment. Recurrence and transformation, altrough rare after surgery, requires post-operative monitoring by an annual CT scan.