Neuroendocrine tumors of the gut, carcinoids have been a diagnostic and therapeutic challenge over the years. The primary diagnostic work-up includes biochemical testing, particularly analysis of chromogranin A and urinary 5-HIAA. The most sensitive localization procedure is somatostatin receptor scintigraphy, which will be supplemented by ultrasonography for liver metastases and concomitant biopsy for histopathological verification. The treatment needs a multimodal approach, including surgery, embolization, tumor-targeted radiotherapy, and biotherapy. Chemotherapy plays a small role in the treatment of classical midgut carcinoids. Two decades ago, the median survival of patients with malignant carcinoid tumors and the carcinoid syndrome was only two years, but today, using this multimodal approach including biotherapy, it is more than eight years for the same category of patients. This may not only reflect the most effective treatment, but also a more active attitude to therapy among physicians. Future therapy will be tumor-biology-based and "tailor-made" for each patient.