Introduction: The most common technique for resection of retroperitoneal tumors it is by far the transperitoneal approach. The extra peritoneal approach could be a viable alternative for selected patients, but it has not been described nor evaluated in clinical trials. Material and methods: This is a retrospective and descriptive study in which we analyzed the results for the two different approaches for retroperitoneal tumors. The clinical records of all patients with the diagnosis of retroperitoneal tumor that were operated at Hospital Pablo Tobon Uribe during a period of time between January 2003 and March 2011 were reviewed manually. Results: Of a total of 37 surgical procedures, 16 were transperitonal, 19 extraperitoneal and two of them required a combined approach. 59% had a resection graded as R0 (50% with the trans peritoneal approach and 68% with the retroperitoneal approach).The mean operating time was 152.96 minutes (159.8 vs. 134.5, respectively). Most of the patients did not need blood transfusion (56,3 vs 78,9%).The complication rate was 30% (25% vs. 31.6%). One patient that died during an extraperitoneal approach operation. Discussion: The extraperitoneal approach is a new a new technique for the resection of retroperitoneal tumors. More studies are required before a full recommendation favoring this technique can be stated.