Cases of primary multiple malignant tumors, with one localized in the stomach, have been studied. In cases of radical surgery, second tumors were detected in 6.2% while in patients with early gastric cancer--twice as many (12.5%). Among second tumors, most frequent were neoplasms of large bowel, urogenital system, head and neck, lung, skin and breast. Radical surgery for gastric cancer was carried out in 94%, palliative resection--6%. Radical surgery for second tumors was performed in 53 (82%), palliative--7 (11%). Surgery for second tumors was used in 38%, combined treatment--27%. Synchronous and, in particular, metachronous tumors were mostly responsible for deaths among those radically treated for stomach cancer. In general, second tumors failed to significantly impact the end results of that pathology (p=0.13). Hence, primary multiple tumors should not be regarded as counterindications for radical treatment, a combined one included, of the either neoplasm, nor does it contribute to postoperative lethality rates. Prior to surgery and during clinical course, it is important to make sure that there are no synchronous or metachronous tumors in sites where they generally occur.