A 20-year-old patient who got injured on his right big toe and complained pain visited to our hospital 9 months ago. Before the patient transferred to our hospital, plain radiographs were obtained at a private hospital and the patient underwent conservative treatment with uncertain diagnosis. However, the symptom was not improved, and he continued to complain intra-articular pain on his interphalangeal joint of big toe during plantarflexion or dorsiflexion. On plain radiographs of our hospital, we observed small bone fragment in his interphalangeal joint of the big toe. On the ultrasonographic images, two loose bodies in the interphalangeal joint were found. Then, we removed the loose bodies as surgical treatment, and the symptom was subsided completely. The purpose of this study is to report the ultrasonographic finding of the loose bodies of interphalangeal joint of the big toe.