Solid-pseudopapillary tumor of the pancreas is a very rare low-grade malignancy, predominantly occurring in adolescent girls and young women. Accurate diagnosis of this unusual tumor is important because the prognosis after surgical resection is excellent. We report a rare case of solid-pseudopapillary tumor of the pancreas in a 22-year-old woman that was misdiagnosed as a pancreatic pseudocyst on abdominal CT scan. This case emphasizes the importance of biopsying the pseudocyst wall at the time of drainage procedure if misdiagnosis is to be avoided. CT scan findings alone can not reliably rule out malignant cystic lesions of the pancreas.