Hepatosplenic gammadelta T-cell lymphoma is an uncommon pediatric disease and is associated with an aggressive and often fatal course. The authors describe the case of an 8-year-old girl who presented with transaminitis and hepatosplenomegaly. Liver biopsy and peripheral blood flow cytometry were diagnostic of hepatosplenic gammadelta T-cell lymphoma. She was treated with multi-agent chemotherapy with cyclophosphamide, vincristine, prednisone, doxorubicin, and high-dose methotrexate but failed to achieve durable remission. She underwent an allogeneic bone marrow transplant from her HLA-identical brother with a preparative regimen including total body irradiation and cyclophosphamide. She is currently alive and has remained in remission for 30 months after transplantation. The authors also review the literature for similar pediatric cases.