Small intestinal neuroendocrine tumors (SI-NETs) are the most common small bowel tumors, they are recognized for their ability to produce hormones causing mesenteric fibrosis and carcinoid syndrome. They tend to have better surgical rate than adenocarcinomas.this work was made as an update on one of the most aggressive small intestine tumors. Presentation of case We discuss here the case of a sixth years old female woman admitted and operated for a small intestine neuroendocrine tumor with peritoneal carcinosis Discussion Neuroendocrine tumors are secreting tumors, locating mainly in the small intestine with a high malignancy risk. At the time of the diagnosis, lymph node, liver metastasis and peritoneal carcinosis are very common. Patients may be asymptomatic or consult for abdominal pain, rarely bowel obstruction, diagnosis is radiologically made and confirmed indeed histologically. Treatment involves surgery, chemotherapy, immunotherapy and radiotherapy and surveillance is assured by biomarkers, endoscopy and Octreoscan when metastatic. Conclusion The SI-NETs are rare but their incidence and prevalence have been increasing. Histologically, diagnosis is confirmed by positive immunohistochemical staining. Treatment and prognosis depend on the grade and stage of the tumor. Immunotherapy will serve as a future treatment modality.