Giant cell tumor of the tendon sheath (GCTTS) in the foot is a rare pathology and is involved in the differential diagnosis of soft tissue tumors of the foot and ankle. Although it can affect any age group, mainly occurs at the 3rd and 5th decade, with being more common in female. Histopathological examination is a major definitive method for diagnosis, although physical examination and radiological imaging are help-full to reach a diagnosis preoperatively. There are many treatment options but marginal excision is the most commonly used one among them. Here in, A 26-year-old pregnant woman with a multi-fragmented mass which is located at extending from the 1st web space to the plantar aspect of the metatarsophalangeal joint (MTP) of left great toe associated with flexor hallucis longus tendon after trauma. She had pain which worse with activity and wearing shoes. After pregnancy, a marginal excision with dorsal longitudinal incision in 1st web space was performed under spinal anesthesia. The lesion was diagnosed as a localized type tenosynovial giant cell tumor. At the last control on the 23rd month, the patient is doing well and there was no recurrence of the lesion. GCSST should be considered in the differential diagnosis of plantar masses of foot. Although, ıt is frequently seen in female, ıt has not been previously reported in a pregnant woman of this extremely rare condition after trauma.