Purpose: To evaluate the relationship between the clinical outcome and the cuff integrity following open repair in large and massive rotator cuff tears using ultrasonography as an imaging modality. Material and Methods: From November 2001 to April 2005, 17 cases(16 patients) who had open repair of tear measuring more than 3cm were assessed with minimal follow-up of 12 months in this study. 6 cases had a large tear and 11 cases a massive tear. There were 6 men and 11 women with a mean age of 52 years at surgery (range, 33 to 72 years). The evaluation consisted of the preoperative and postoperative shoulder scores according to UCLA shoulder scoring system and Visual analogue scale (VAS). Ultrasonography was performed by a experienced musculoskeletal physician at a minimum of 12 months postoperatively to evaluate the postoperative cuff integrity. Results: Retear were detected in four of seventeen cases. Regardless of the presence of recurrent tear, 14 cases had UCLA score of more than 29 points (good grade). All 17 had an improvement in the functional score, which increased from an average of 15.1 to 31.2 points. All cases showed pain relief and five cases had no pain. Sixteen cases except one had the range of motion of forward elevation above $90^{circ}$. Conclusion: Open rotator cuff repair in large and massive tears showed low retear rate. At a minimum of twelve months follow-up, all cases had improvement on UCLA score, pain relief, increased range of motion of the shoulder regardless of retear. And the correlation between recurrent tear and function score was not statistically significant.