Primary duodenal cancer is a rare disease. We examined 8 resected cases of duodenal cancer at our hospital from June 2003 to February 2022. Patients with resected duodenal cancer had an average age of 69.3 years(45-84 years), with a male-female ratio of 3 : 5. Of the 8 cases, 6 cases were adenocarcinomas and 2 were neuroendocrine carcinomas. Among those with adenocarcinomas, 3 cases were Stage Ⅰ, while Stage ⅡA, ⅢA, and ⅢB accounted for one case each(UICC 8th edition). Five patients underwent a pancreaticoduodenectomy(PD), while 1 underwent partial duodenal resection. Except for 1 case of Stage ⅢB(death from tumor recurrence in 1 year), tumor recurrence was not observed in the 5 remaining cases(survival period; >1 month to >97 months). The patient with a pT3pN1M0, Stage Ⅲ neuroendocrine carcinoma underwent a partial duodenal resection due to poor cardiac and renal function. Meanwhile, the patient with a pT4pN0M0, Stage Ⅲ neuroendocrine carcinoma underwent a PD. The survival time was 123 months for the former(death from other diseases, no tumor recurrence)and 7 months for the latter(death from recurrence).