Primary retroperitoneal tumors are a rare group of neoplasms that often prove to be a real therapeutic challenge. The clinical picture is in most cases nonspecific, being the result of nearby tissue and organ compression, displacement and/or invasion, and it usually includes a variety of deceiving signs and symptoms that may lead to diagnostic errors. During the course of the disease, up to half of the patients diagnosed with retroperitoneal tumors can develop gastrointestinal symptoms, the incidence of such symptoms significantly increasing with tumor size. Therefore, symptoms such as abdominal distension, diffuse abdominal pain or epigastric pain mimicking acute pancreatitis, diarrhea, constipation, jaundice, hematemesis, melena and hematochezia can be found. The mainstream treatment for primary retroperitoneal tumors is surgical excision, chemotherapy and radiotherapy but associated with poor results. Due to their rarity, as well as to the complexity of these tumors, patients should be managed in high volume centers that allow the possibility of a multidisciplinary approach.