Ostehochondroma is a common primary benign bone tumor, and is mostly asymptomatic. Symptoms are related complications due to compression on the adjacent nerve. The sciatic nerve compression secondary to osteochondroma has rarely been reported. A 21 year-old man had right hip pain radiated to the right lower extremity. In a radiological evaluation, bone mass was detected at the right ischial tuberosity. After dynamic ultrasonography, we excised the bone mass and decompressed the sciatic nerve. The bone mass was diagnosed as osteochondroma by pathologic evaluation. We report the case with a review of the literature.