We report the first documented case of a solid and papillary tumor of the pancreas (SPT) complicating agenesis of the dorsal pancreas. A 28-year-old female patient was referred to our hospital for a pancreatic tumor detected at a local hospital. The laboratory findings were all within normal limits. Diagnostic images revealed absence of the dorsal pancreas and the presence of a tumor located in the head of the pancreas. The tumor was solid, well demarcated, noncalcified, and hypovascular. Fine-needle aspiration cytology revealed that larger cell clumps often had a branching papillary appearance, with multiple layers of tumor cells surrounding central vascular stalks; a preoperative diagnosis of SPT was made. At surgery, on February 10, 1999, the tumor was found to have clear margins, and it showed no signs of direct invasion of adjacent structures. No metastases were found in the liver or the local lymph nodes. Accordingly, partial resection of the pancreas, including the entire tumor, was performed, and, thus, almost the entire head of the pancreas could be saved. Microscopic examination of the resected specimen yielded findings compatible with SPT. No recurrences, and no impairment of pancreatic endocrine or exocrine function have been noted since the operation.