Primary squamous cell carcinoma of the pancreas or of the stomach is rare and represents a controversial entity. The unusual case of a 50-year-old woman with a large squamous cell carcinoma located in the celiac area and involving liver, stomach and pancreas, is reported here. The patient underwent complete surgical resection. The microscopic diagnosis was well-differentiated squamous cell carcinoma without glandular structure. Following the procedure, search for another possible primary lesion (esophagus, anus, colon, lung, head and neck, pelvic floor) was performed. This search was negative. In this context, final diagnosis was primary gastric or pancreatic squamous cell carcinoma. Local recurrence located in the eso-jejunal anastomosis was discovered three years later. Subsequent radiation combined with chemotherapy was instituted, allowing complete remission. During the subsequent 27-month follow-up, no local or systemic recurrence was observed. Pathogenesis of gastric as well as pancreatic primary squamous cell carcinoma remains obscure and controversial. These tumors usually have a very poor prognosis with rapid vascular and lymphatic involvement. Nevertheless, favorable outcome seems possible, as exhibited in our patient.