BACKGROUND Solid pseudopapillary tumor (SPT) is a rare disease with low-grade malignancy potential of the pancreas. SPT accounts from 0.13% to 2.7% of all exocrine pancreatic tumors. We report an unusual case with a large solid pseudopapillary tumor that was diagnosed and treated in our pediatric hospital. CASE REPORT A 15-year-old girl was incidentally found to have an abdominal mass on ultrasound examination. Computed tomography (CT) scans showed a well-defined tumor that was raised in part of the tail and body of the pancreas. The tumor size at greatest diameter was 18.2 cm. A mass excision was performed to remove the whole tumor, and the histopathological findings confirmed SPT without evidence of malignancy. CONCLUSIONS SPT is a rare disease that mostly affects young female patients. The clinical symptoms of this disease are unspecific. The prognosis of SPT is good, even in case of distant metastasis. Close follow-up is required to detect metastasis so the appropriate treatment method can be chosen.