Arthroscopic examination of the hip joint was performed in mature and juvenile horses, using a lateral approach and standard or long instruments depending on body weight. Nine hip joints were examined in three cadavers and four anesthetized horses. The lateral, cranial, and caudal regions of the femoral head and acetabulum were accessible, and, after distraction of the limb, the ligament of the head of the femur and the acetabular notch were also visible. In small horses, the medial regions of the hip joint were visible but were inaccessible in larger horses. Iatrogenic injury to the sciatic nerve or periarticular vasculature was not evident at necropsy examination. Six horses with lameness localized to the hip joint were examined arthroscopically. At surgery, two horses had tearing of the ligament of the head of the femur, two horses had osteochondrosis of the femoral head or acetabulum, and two horses had degenerative joint disease, one associated with a rim fracture of the caudal aspect of the acetabulum and the other of indeterminant origin. Improvement after debridement occurred in one of the horses with partial disruption of the ligament of the head of the femur and in both horses with osteochondrosis. Diagnostic and surgical arthroscopy of the hip can be accomplished in foals and weanlings using standard equipment, but, in adults weighing more than 300 kg, longer instruments are required and the ease of access and the visible extent of the hip joint is considerably reduced.