The diagnosis of synovial chondromatosis (SCM) is usually delayed, as the arthroscopic-guided synovial biopsy is postponed owing to its invasive nature. We report the timely diagnosis of a giant solitary synovial chondromatosis of the hip in a 32-year-old woman using ultrasound-guided synovial biopsy. This technique revealed to be safe and successful in the diagnosis of SCM, when the imaging studies were obscure. Moreover, it avoided the potential arthroscopy-associated complications. We recommend ultrasound-guided synovium biopsy as a less invasive and less complicated technique for the early diagnosis of SCM in future workouts.