Neurofibromatosis type 1 (NF1) is a genetic disease characterized by neoplastic and nonneoplastic disorders involving tissues of neuroectodermal and mesenchymal origin. The mainly involved districts are skin, the central nervous system, and eye and there is a wide range of severity of clinical presentations. Abdominal manifestations of NF1 include five kinds of tumors: neurogenic tumors (neurofibromas, malignant peripheral nerve sheath tumors [MPNSTs], and ganglioneuromas); neuroendocrine tumors (pheochromocytomas and carcinoids); nonneurogenic gastrointestinal stromal tumors (GISTs); embryonal tumors; and miscellaneous. The present experience depends on the participation in the National Project for Diagnosis and Treatment of Rare Diseases. In the group of patients with a diagnosis of von Recklinghausen disease, 10 patients underwent surgical treatment for gastrointestinal and retroperitoneal tumors associated with NF1. Three patients underwent adrenalectomy for pheochromocytoma (in one case associated with jejunal wall neurofibroma); two patients were found to be affected by MPNST (recurrent and unresectable in one case). One patient was affected by giant gastric GIST and jejunal neurofibroma; two patients were affected by extraperitoneal neurofibroma (pararenal and pararectal position); one patient was affected by giant colic neurofibroma and one patient was affected by retroperitoneal bilateral plexiform neurofibromas. Early diagnosis of these abdominal manifestations is very important because of the risk of malignancy, organic complications (such as pheochromocytoma), or hemorrhagic–obstructive complications such as in case of tumors of the gastrointestinal tract (GISTs and neurofibromas). The importance of an annual clinical evaluation on the part of a multidisciplinary pool of clinicians in highly specialized centers allows early detection of complications and of neoplastic transformation. Genetic screening allows preclinical diagnosis with a sensibility of 95 per cent. Further studies are necessary to detect predictive factors of malignant tumor development of severe clinical conditions.