This prospective randomized study compares the clinical results of immediate passive mobilization versus delayed mobilization in the rehabilitation of rotator cuff repair during the early postoperative period. The mobilization group (79 patients) received immediate daily passive mobilization. The immobilization group (51 patients) was immobilized for 4 weeks until physiotherapy was started. Passive range of motion was noted preoperatively, at 6 weeks and 4 months. Strength was measured preoperatively and at 4 months. Constant-Murley, Simple Shoulder Test, SPADI and UCLA scores were noted at baseline and at 4 months. Ultrasonography was performed at 6 weeks to exclude early failures of repair. We noted no significant difference between the two groups regarding range of motion at 6 weeks and range of motion, strength and functional outcome scores at 4 months. Ultrasound didn't show a difference in healing at 6 w in either of both groups. Both rehabilitation protocols seem applicable as well as safe in the early post-operative phase.