Neuroendocrine tumors (NETs) are a group of rare malignancies characterized by heterogeneous clinical and biological presentations. Their estimated annual incidence ranges from 3 to 6 cases per million inhabitants, with a notable rise in prevalence due to improved diagnostic capabilities and medical awareness. Gastrointestinal NETs predominantly affect the small intestine (~45%), followed by the rectum, appendix, colon, and stomach. Despite advancements in imaging modalities such as CT, MRI, and somatostatin receptor-based PET-CT scans, the diagnosis of small intestinal NETs remains challenging due to nonspecific symptoms, frequently leading to delayed recognition until advanced disease stages. Surgical resection with comprehensive lymphadenectomy remains the cornerstone of curative management for localized disease, offering improved survival outcomes when R0 resection is achieved. Nevertheless, recurrence rates remain high, underscoring the critical importance of postoperative surveillance. This review provides a comprehensive synthesis of recent literature regarding the epidemiology, clinical manifestations, diagnostic methods— including imaging and immunohistochemical markers—and therapeutic approaches, particularly emphasizing surgical management strategies. A clinical case example is integrated into the review to illustrate the real-world complexity and challenges in the diagnosis, treatment, and follow-up of patients with small intestinal NETs.