Neuroendocrine tumors (NETs) are a diverse group of neoplasms that originate from neuroendocrine cells throughout the body. Diagnosing NETs presents unique challenges due to their varied presentation, morphology, and biological behavior. This article provides an overview of the key diagnostic principles relevant to general pathologists, emphasizing the importance of a multidisciplinary approach that integrates clinical, radiological, histopathological, and immunohistochemical data. The emergence of new markers as well as recent advances in molecular pathology and the application of grading systems are discussed, highlighting their impact on prognosis and therapeutic strategies.