Context Bariatric surgery has become the most effective method for producing weight loss in obese patients. The evaluation of improvement of comorbidities and changes in the quality of life are important outcome factors; however, it is necessary to investigate whether they persist over the long term. Methods A cross-sectional study was conducted on 143 obese patients from our institution from February 2007 to February 2008. These patients were divided into five independent groups, one being a control group, plus four other groups with 1, 2, 3, 4 or more years following surgical Roux-en-Y gastric bypass with a silicon ring banded. quality of life forms and anthropometric measurements were performed and its scores correlated with social factors, weight loss success, and status of obesity-related conditions. Results For the group that was 1 year postoperative, a significant percentage of excess body weight loss (EBWL%) of 81.7% was observed. The groups with 2, 3, 4 or more years of post-surgical follow-up showed a EBWL decline, but without significant difference. The main comorbidity percentages in all patients who had the surgery was as follows: 69.7% for hypertension; 88.2% for diabetes mellitus; and 27.5% for arthropathy. There was a significant decrease in the rate for diabetes resolution (P = 0.035) observed by evolutionary assessment of the comorbidity resolution. The results obtained by BAROS were good, very good, or excellent in more than 96% of patients in all evaluations that were performed. The use of the Moorehead-Ardelt Questionnaire (M/A) demonstrated improvement in the quality of life. Moreover, the quality of life, when evaluated through SF-36, also showed improvement in all related areas after 1 year; however, after 4 years, improvement remained elevated only in the areas of general state of health and functional capacity. Conclusions The Roux-en-Y gastric bypass procedure was able to achieve EBWL of 81.7% after 1 year following surgery, remaining steady with little decline after this period. Important resolution of comorbidities, such as hypertension and diabetes, was also seen. Immediate surgical outcomes assessed by SF-36 and M/A in the area of quality of life were satisfactory, but the general state of health and functional capacity areas were sustained satisfactory at a later time only.