An 8-month-old captive male reticulated giraffe (Giraffa camelopardalis reticulata) developed an acute lameness (grade IV/V) of the right forelimb, with swelling of the metacarpophalangeal joint. A traumatic injury was suspected based on clinical, radiographic, and arthroscopic evaluation. Several abnormalities were identified arthroscopically, including synovitis, cartilage damage, and an osteochondral fragment. Medial collateral ligament damage was also suspected based on radiographic evaluation. Arthroscopy provided a means of diagnosis and treatment of the abnormalities identified. The lameness in this giraffe resolved within 6 week following arthroscopic surgery.