There has been remarkable advancement in arthroscopy of the knee since Watanabe's 21 arthroscope in 1959. Our understanding of knee pathology has been advanced and new syndromes have been described. The internal structures of the knee can now be visualized with magnification-promoting diagnostics. Equipment has been designed specifically for knee arthroscopy, allowing for advances in technical procedures and for surgery not heretofore anticipated. Skilled arthroscopists can perform meniscectomy routinely. The next few years should allow development of instruments for continued advancement of techniques and also to allow clinical research to assess the value of many of the procedures in use today. Arthroscopy, both diagnostic and therapeutic, is a safe procedure with minimum morbidity. Moreover, in the near future, arthroscopy will assuredly advance to become routine in several other joint, particularly the ankle and shoulder.