Repair of massive rotator cuff tears is technically difficult but often feasible. Technical and biological challenges to a successful repair include inelastic poor-quality tendon tissue, scarring, muscle atrophy, and fatty infiltration. Fatty infiltration of the involved rotator cuff muscles has been identified as an important negative prognostic factor for the outcome after repair of massive rotator cuff tears. Tendon transfer is a good option for young patients and manual laborers with an irreparable massive rotator cuff tear. Arthroplasty can be considered for the treatment of symptomatic massive rotator cuff tears in patients who have glenohumeral arthritis.