In the dog, as in man and the horse, arthroscopy has an important role in treatment of joint disease. In the shoulder, elbow, and stifle joints, surgical arthroscopy can and should replace the classical surgical methods of treating osteochondrosis lesions. In elbow and tarsocrural joint disorders, the diagnostic potentials of arthroscopy are evident. With the established techniques, not only can the lesions be diagnosed with accuracy, but they can also be treated within the same procedure, making arthroscopy the treatment of choice to deal with osteochondrosis lesions. Without a doubt, arthroscopy will play an important role in the understanding of the etiopathology of different joint diseases, especially within the elbow joint, where so many questions remain unresolved. The advantages of arthroscopy in the diagnosis and treatment of osteochondrosis have also encouraged other veterinary surgeons to adopt the technique. In the developmental stage of arthroscopy in the dog, a frequently expressed comment was that arthrotomy was as valuable and as easy (or easier) to perform as arthroscopy. Now that the advantages of arthroscopy have been demonstrated, the skepticism has changed into enthusiasm. The same evolution is noted with arthroscopy in both man and the horse.