Sarcomatoid transformation of intrahepatic cholangiocarcinoma is rarely found but usually has very poor prognosis due to the lack of effective approaches for early detection and its aggressive nature. We report a case of this tumor type, in a 60-year-old man who was referred to our hospital for further evaluation of screening-detected, asymptomatic hepatic lesion. Clinical diagnosis was elusive despite performance of different imaging modalities and a transcutaneous liver biopsy. Pathology of the surgically resected tumor demonstrated intrahepatic sarcomatoid cholangiocarcinoma. In our case, tumor cells expressed strong immunoreactivity to both cytokeratin-19 and vimentin. We assume the relatively good prognosis of this patient would be expected because surgery played a critical role at an early stage of the tumor.