A giant cell tumor of tendon sheath (GCTTS) is a soft tissue tumor consisting principally of a proliferation of synovial cells arising from a tendon sheath. GCTTS is the second most common tumor of the hand in general and a majority of GCTTS cases are in patients between 20 and 50 years of age, whereas pediatric cases of GCTTS are uncommon. This report presents the case of a nine-year-old girl with GCTTS arising on her right index finger.