Solid pseudopapillary tumors (SPTs) are a rare pancreatic neoplastic lesion. Familial aggregation has not been reported in this disease. The objectives of this study were to report the history, clinicopathological features, and gene mutations of 3 familial cases of SPT. Three female cases of SPT presented in 1 family. Eight family relatives, 5 healthy volunteers, and 8 patients with SPT acted as controls. Histological examination and immunohistochemistry were performed on the surgical tumor specimens. Polymerase chain reaction-single-strand conformation polymorphism and gene sequencing were performed on genomic DNA extracted from blood. All 3 patients underwent surgical treatment, 2 patients died (3 months and 5 months after surgery), whereas neither recurrence nor metastasis was observed in the other patient during 2-year follow-up. The tumors from the 3 cases had identical immunoreactivity to a series of molecular markers. A Leu104Val mutation of protease serine 1 (PRSS1) was observed in the familial patients and 2 healthy male family members; no β-catenin or adenomatous polyposis coli mutations were detected in the familial cases. This study indicates the possibility of genetic involvement in the pathogenesis of SPT. Family history may be a positive predictive factor for malignancy in SPT.