Objective: To evaluate the short term and 1-year follow-up functional effects of a physiotherapy program in patients over 60 years of age with massive and irreparable Rotator Cuff (RC) tear. Methods: A total of 96 patients with massive and irreparable RC tear were prospectively recruited. All patients were treated with a 12-week physiotherapy program. Three evaluations were performed, at the beginning, at the end of the treatment and at one year of follow-up. The Constant-Murley questionnaire was used to assess shoulder function, the DASH questionnaire for upper limb function, and the Visual Analogue Scale (VAS) for pain intensity. Results: At the end of the treatment, all the variables showed a clinically and statistically significant difference (p < 0.05). At one year of follow-up, the Constant-Murley showed an increase of 26.5 points (Cohen's d = 1.7; 95% CI 23.5 to 29.5; p < 0.001), DASH showed a decrease of 31.4 points (Cohen's d = 2.2; 95% CI 28.5 to 34.3; p < 0.001), and the VAS showed a decrease of 3.9 cm (Cohen's d = 3.6; 95% CI 3.6 to 4.1; p < 0.001). Conclusion: In the short term and 1-year follow-up, a physiotherapy program showed clinically and statistically significant results in all functional variables in patients older than 60 years with massive and irreparable RC tear.