Purpose: Solid pseudopapillary tumor (SPT) of the pancreas is a rare tumor mostly present in young women of age 20-30 years, with a good prognosis and low malignant potential. In this report we suggest endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) as an effective diagnostic approach of this tumor. Case: 32 year-old African American female who was being studied for myeloproliferative disorder because of high WBC count for 3 years. An ultrasound of the abdomen done for possible splenomegaly revealed a large 19.3 x 12.2 x 14.2 cm heterogeneously echogenic abdominal mass that fills the upper abdomen anteriorly. The patient reports having early satiety 4-6 months and mild nausea for 6-8 months. Laboratory studies included normal values for the glucose, liver chemistries, iron studies, LDH, CA19-9, AFP, CEA, and CA125. White cell count 18,000, neutrophils 56%, lymphocytes 28%, monocytes 13%, Hemoglobin 14 g/dl, Hematocrit 44%, platelets 342,000. CT of the abdomen demonstrated a heterogeneously enhancing mass within the mid-abdomen, which extends from the level of the greater curvature of the stomach inferiorly to the level of the lower pole of the left kidney, measuring 13.5 x 17.8 x 17.1 cm and causing lateral displacement of the gastric antrum and proximal duodenum as well as displacement of the pancreatic body and head. There were several enlarged mesenteric lymph nodes and splenic vein occlusion with multiple collateral vessels. EUS revealed a large heterogeneous mass of the retroperitoneum adjacent to the posterior gastric wall. The mass had multiples small cavitations, was hypoechoic with foci of hyperechogenicity suggesting hemorrhage within the mass. FNA was performed using an Echotip Ultra 22 gauge needle in 3 passes. The confirmatory inmunohistochemical diagnosis revealed SPT of pancreatic type and stained positive for vimentin and weakly positive for AFP. Conclusion: SPT of the pancreas is an unusual tumor; it has female predilection with a 10:1 predominance over men, is indolent, and carries better prognosis than other pancreatic tumors. Metastatic disease can occur in 15% of cases usually involving the liver or mesenteric lymph nodes. Clinical manifestations include abdominal pain, fullness, nausea and vomiting due to a bulky tumor compressing local structures in the upper abdomen or can be asymptomatic. Radiological features may be inconclusive. EUS-FNA is useful to confirm the diagnosis. Surgery can be curative in most cases. We propose the use of EUS-FNA as a preoperative diagnostic tool in patients with clinical and radiologic suspicion of SPT of the pancreas. SPT should be considered in the differential diagnosis of large retroperitoneal masses, particularly in young women.