BACKGROUND: Primary multiple carcinomas are not observed very frequently. Research has been focused mainly on such issues as the frequency of occurrence of primary multiple carcinomas, the identification of high-risk groups, early diagnosis, treatment methods, and prognosis. The purpose of this article is to present our own experience in the surgical treatment of patients with multiple cancers. MATERIAL AND METHODS: The paper presents 13 patients of both sexes with primary multiple carcinomas. Four of these patients were diagnosed with synchronous carcinomas, the remaining patients with metachronous. The malignant tumors were variously localized. In the group with synchronous carcinomas, the malignant tumors were located in esophagus, stomach and rectum, pancreas and right ovary, esophagus and palatine tonsil. In the group with metachronous carcinomas, another cancer was diagnosed 12 months to 24 years after the treatment of the first carcinoma was completed. The other cancers were located in esophagus, stomach, pancreas, lung, and the skin of the cheek. Nine patients were qualified for surgical treatment on the basis of the preoperative TNM classification. Various surgical procedures were used. In cases of synchronous multiple carcinomas one-stage operations were preferred. RESULTS: Significant postoperative complications were noted in 2 cases. In the first case, a recto-sigmoid anastomotic leak resulted in increased circulatory and renal insufficiency, leading to the patient's decease. In the second case, a massive gastric hemorrhage after ileocoloesophagoplasty led to respiratory insufficiency, which was the cause of the patient's decease. Two patients died within 12 months after surgical treatment. In the first case cancer recurrence was the cause of death; in the second, myocardial infarction. Long-term follow-up was focused on 5 patients with no cancer recurrence during the period from 12 months to 4 years after surgical treatment. CONCLUSIONS: The results of this study suggest that patients who have had a first cancer successfully treated are at higher risk of developing a subsequent cancer, and that regular follow-up with thorough examination in patients successfully treated for cancer may lead to the early detection of a subsequent cancer when it is still at a curable stage.