The relationship of colorectal carcinoma with polyps was studied retrospectively in 1202 patients. The incidence of synchronous carcinoma (SC) and metachronous carcinoma (MC), prognosis, and recurrence patterns were studied. Synchronous polyps (SP) were found in 36% of the patients. SC was found in 4.4% of the patients, and MC developed in 3.5% of patients. The incidence of SC and of MC increased with SP, and varied according to number, size, and histologic features of the polyps. The adjusted 5-year survival rate was improved in patients with SP compared with those without SP, both overall (79% versus 64%, respectively) and by Dukes' Stage B (87% versus 73%, respectively) and Dukes' Stage C (56% versus 39%, respectively). The pattern of relapse was the same for the SP and non-SP groups. Subtotal colectomy is recommended for colorectal carcinoma and SP in good-risk patients.