Aims: The purpose of this study was to evaluate the efficacy of the inverted Delta 3 prosthesis in nonreconstructable massive rotator cuff tear. Methods: 31 inverted Delta 3 prostheses were performed between October 1999 and February 2002. The average age was 72.8 years old (65–84) and the average follow-up was 17.8 months (3–36). A deltopectoral approach was performed in all cases. Rotator cuffs were found to be nonreconstructable in all 31 cases. Results: Functional results were assessed using the Constant score. Constant score was improved from 32.1 preoperatively to 59 postoperatively. Forward flexion increased from 52 degrees to 135 mean degrees. 85% of the patients were satisfied. Two complications occurred: a stupor of the radial nerve and a ditching of the cementless humeral component. Conclusions: Inverted Delta 3 prosthesis represents a successful choice for cases of irreparable rotator cuff and gleno-humeral lesions in old patients with an excellent deltoid and a good glenoid bone stock. It reduces pain and improved function in all patients. The loosening of glenoid component is not frequent with a short-term follow-up.