AIMS Due to the severity of colonic injuries and their frequency on the left side, we study relationships between the left kidney and the descending colon to identify subjects at risk of colonic perforation during percutaneous surgery of the left kidney. MATERIAL AND METHODS Over a period of 3 years we exploited abdominal CT scans for 1084 patients in both sexes without any visceral or parietal lesions. We studied the situation and relationships of the lumbar part of the descending colon in the left pararenal space using a conventional grid technique. RESULTS The preferential site of the colon in both sexes was laterorenal in 55.8% of cases. We also found the descending colon in a posterolateral situation in 21.1% of cases, and in an anterolateral situation in 14.8% of cases. In women, the posterolateral situation was twice more common than in men, but we did not observe any post-renal situation. Laterorenal and posterolateral situations were the most frequent in patients less than 50 years; while beyond this age 70.1% of subjects had a laterorenal type. CONCLUSION Sex and age affect topographic variations of the lumbar part of the descending colon in the left pararenal space. Although they are rare or aberrant, some locations exist and should not be ignored by the operator. These locations are risk factors of colonic lesion during percutaneous approach of the left kidney.