This paper emphasizes the diagnosis and therapeutic difficulties in primary retroperitoneal tumors. There were analyzed 68 primary retroperitoneal tumors (1992-2002): 16 (23.5%) benign tumors, 39 (57.35%) malignant tumors and 13 tumors with unknown histological structure. The preoperative diagnosis was clinically suggested and confirmed by ultrasound and CT examination; the operability was always established by laparotomy. All cases were operated on: complete resection of tumor was possible in 39 cases (57.35%); partial resection in 11 cases (16.17%) and 18 (26.47%) cases were inoperable. There were 5 major intraoperative vascular lesions: 1 inferior vena cava lesion, 1 superior mesenteric vein lesion, 1 left common iliac vein lesion and 2 lumbar artery lesions. Postoperative mortality was represented by 2 cases. Postoperative complication was represented by 3 postoperative hemorrhages, 2 severe pulmonary infections, 1 postoperative evisceration, 1 postoperative acute pancreatitis and 1 acute myocardial infarction. In conclusion the primary retroperitoneal tumors represent a challenge for all surgeons, especially due to surgical approach difficulties, because of problems in tumors intraoperative exploration and resection and because of difficulties in hemostasis.