Among lung tumors, well-differentiated neuroendocrine carcinomas are often misdiagnosed or may go unrecognized. Nineteen cases of well-differentiated neuroendocrine carcinoma (WDNC) were assessed at the National Cancer Institute of Milan over a ten-year period. There was only one woman and the age range was 50 to 77 years. Most of the patients were smokers (83 percent). All tumors were radically resected. There were 12 lobectomies, two sleeve-lobectomies, three bilobectomies, one pneumonectomy, and two segmentectomies (one patient had two synchronous WDNCs). There was neither operative mortality nor major complications. Sixteen tumors were stage 1, three were stage II, and one was stage IIIa. Five patients had adjuvant chemotherapy (cyclophosphamide, doxorubicin, and vincristine [CAV] regimen). One patient was given local or regional radiotherapy. In ten patients the tumors recurred, even though four had had adjuvant treatment. The brain was the first site of metastasis in seven cases. The pathologic stage seemed not to be closely related to the appearance of metastases (six patients with stage I disease had recurrences). Only two patients with recurrence were still alive 12 and 103 months after the procedure. The percentage of survival for patients with stage I disease after more than 100 months was 68 percent. WDNC is similar to small-cell lung carcinoma (SCLC) with regard to the neurotropism of metastases. Surgery is curative for more than one half of the patients with localized disease. Therefore, multimodal therapy, probably based on tumor behavior and investigations of tumor markers, is advisable.