Enchondromas are benign cartilaginous tumors and tend to present in small bones of hands and feet. Malignant transformation, though rare, is seen more often in multiple rather than solitary enchondromatous. A 70- year-old woman presented with swelling and pain lasting for years at the index finger of the right hand. Excisional curettage material of the mass revealed to be entirely an enchondroma. Seven months later, the lesion recurred at the same localization and amputation of the finger was performed. This time the tumor was found to be transformed into an intermediate grade (grade II) which demonstrated chondrosarcoma intermingled with classical enchondromatous areas. Enchondromas arising at the hands and feet very rarely transform into chondrosarcomas. Since enchondromas at this site often show histological and clinical features suggestive of malignancy, it is often is difficult to make a histological distinction between benign cartilaginous tumors and chondrosarcomas. Detection of radiological as well as pathological findings are essential for differential diagnosis. This case is remarkable for she has a solitary enchondroma located at the index finger of the right hand that transformed into chondrosarcoma in seven months.