BACKGROUND: The hip joint is becoming increasingly recognized as a source of groin pain and, in the authors' experience, buttock and low back pain. OBJECTIVES: To determine the range of pathologic diagnoses, clinical presentation, and the correlation between magnetic resonance arthrographic, ultrasonographic, and arthroscopic findings in the hip joint. METHODS: We prospectively studied 25 consecutive hip arthroscopies to determine the range of pathologic diagnoses, clinical presentation, and the correlation between magnetic resonance arthrographic, ultrasonographic, and arthroscopic findings. RESULTS: All of the hips arthroscoped had pathology. Back pain and hip pain were the 2 most common presentations. The only consistently positive clinical test result was a restricted and painful hip quadrant compared with the contralateral hip. Of the 17 patients whose flexion, abduction, external rotation (FABER) test results were reported at the time of examination, 15 (88%) were positive, and 2 (12%) negative. Plain radiographs were normal in all patients. All but 1 patient underwent magnetic resonance arthrography. Although specificity of 100% was achieved in our study, the sensitivity was significantly lower, with a relatively high number of false negatives. Hip arthroscopy proved the definitive diagnostic procedure for intraarticular pathology. CONCLUSIONS: Hip pathology, particularly labral pathology, may be more common than has been previously recognized. In those patients with chronic groin and low back pain, a high index of suspicion should be maintained. Clinical signs of a painful, restricted hip quadrant and a positive FABER test result should suggest magnetic resonance arthrography in the first instance, but a negative magnetic resonance image should not preclude hip arthroscopy if there is high clinical suspicion of hip joint pathology.