Gastroesophageal junction adenocarcinoma is a rare type of cancer of the esophagus. It is usually diagnosed in advanced stages and much less frequently in the earlier stage, where surgical treatment is essential. Surgical treatment is also essential in kidney cancer. The occurrence of synchronous malignancies with an esophageal malignancy is a well-described phenomenon with an incidence ranging from 3.6 to 27.1%. To the best of our knowledge, only 11 cases of synchronous esophageal and renal cell carcinoma (RCC) have been previously described. We present a patient operated simultaneously for cancer of the gastroesophageal junction with synchronous renal cell carcinoma. The finding in the kidney was accidentally discovered by the routine CT scan on the occasion of the relatively early carcinoma of the gastroesophageal junction detected by upper endoscopy. The patient was admitted to the Thoracic Surgery Department, where Ivor-Lewis gastroesophagoplasty and right nephrectomy simultaneously were performed. The patient was followed for 5 years without evidence of disease progression.