Persistent descending mesocolon(PDM)is a fixation abnormality caused by the failure of the left colon to fuse with the parietal peritoneum during embryological development. In cases of PDM, extensive adhesions and characteristic vascular branching anomalies are often observed. Therefore, great care must be taken to avoid intestinal injury due to adhesion dissection and intestinal ischemia due to vascular damage. Particularly during lymph node dissection for sigmoid colon or rectal cancer, it is recommended to preserve the left colic artery(LCA)or assess blood flow using indocyanine green(ICG)fluorescence imaging to ensure adequate blood supply to the oral side of the anastomosis. In this study, we report 6 cases of colorectal cancer surgery involving PDM that we have experienced.