Objective To explore the clinical characteristics and prognosis of multiple primary colorectal carcinoma. Methods The clinical data of 42 cases of colorectal cancer admitted to the First Affiliated Hospital of Nanjing Medical University between January 2013 and December 2018 were retrospectively analyzed. The clinicopathological features, diagnosis, treatment and prognosis were summarized. Results There were 42 patients with multiple primary colorectal carcinoma, accounting for 1.20% (42/3 499) of all colorectal carcinoma patients in the same period. The main pathological type was adenocarcinoma. Among them, 32 cases were synchronous multiple primary carcinoma. And the age ranged 38-86 years old, and the median age was 66 years old. A total of 73 colorectal cancer lesions were detected, mostly located in the proximal colon, sigmoid colon and rectum. A total of 527 lymph nodes were detected, and the positive rate was 1.9% (10). Patients with positive lymph nodes accounted for 37.5% (12/32), including 27 cases of multiple primary carcinoma, 3 cases of triple primary carcinoma, 2 cases of five primary carcinoma. The 1-year and 3-year overall survival rates were 83.75% and 74.38%, respectively. There were 10 cases of metachronous multiple primary carcinoma. Patients were aged 33-86 years old. The first cancer was mostly located in the rectum and sigmoid colon, and the second cancer was mostly located in the ascending colon area. A total of 276 lymph nodes were detected, and the positive rate was 12.3% (34). The 1-year and 3-year overall survival rates were 100.00% and 66.67%, respectively. Conclusions Multiple primary colorectal cancer is not rare clinically and its distribution shows a certain regularity. More attention should be paid to improve the early diagnosis rate. Early operation is needed to improve the survival rate of patients. Key words: Colorectal neoplasms; Neoplasms, multiple primary; Clinical characteristics; Prognosis