Abstract: Synchronous multiple primary carcinomas refers to 2 or more than 2 kinds of different primary malignant tumors develop synchronously or in 6 months. The incidence of synchronous multiple primary carcinoma is low. A patient with esophageal basaloid squamous cell carcinoma (BSCC) and gastric adenocarcinoma was admitted to the First People′s Hospital of Lianyungang in October 2011. The main symptom of this patient was dysphagia, and multiple lesions were found in esophagus, cardia and stomach fundus by gastroscopy respectively. On computed tomography image, eminence lesion in esophageal midpiece and wall thickening from esophagus cardia to stomach fundus were displayed and were both enhanced slightly by enhancement scanning. The esophageal and cardia tumors were resected via left thoracic approach, and postoperative pathological examination revealed esophageal BSCC and moderately differentiated adenocarcinoma of cardia respectively. Comedo necrosis and red basal membrane material were seen under light microscope. The expressions of cytokeratin 5/6 and P63 were positive, the expression of cytokeratin L was weak positive and the expressions of synaptophysin, chromogranin A and CD117 were negative. The patient suffered from pleural effusion and multiple liver metastases after 4 months follow up and died of liver metastases in May 2012. Multiple primary carcinomas including esophageal BSCC and gastric adenocarcinoma are rarely seen in clinical practice. Their diagnosis and differential diagnosis mainly depend on histological morphology and immunohistochemical method. Surgical resection combined with postoperative radiotherapy and chemotherapy is selectable, but the prognosis is poor.