Arthroscopy has improved our diagnostic assessment of rotator cuff disease, especially in understanding patterns of articular surface partial-thickness tears. Arthroscopic subacromial decompression is a proven and reliable alternative to open acromioplasty. Despite continued controversy, most partial-thickness rotator cuff tears may be satisfactorily treated by arthroscopic debridement and decompression. The role for debridement and decompression without repair for full-thickness rotator cuff tears seems less than initially suggested, as several recent independent studies have documented results inferior to open repair. Arthroscopically assisted mini-open repair of small, full-thickness rotator cuff tears is a reliable procedure. Arthroscopic repair appears promising, but is not yet well enough documented to be considered a standard treatment.