OBJECTIVES: Correct clinical management of morbid obese patients does not begin and neither ends with bariatric surgery. The aim of this study was to evaluate the association between number of medical follow-up visits after surgery and patient outcomes in morbid obese patients undergoing roux-en-Y gastric bypass (RYGB). METHODS: This is a database (DATASUS) retrospective cohort study. Inclusion criteria was patients undergoing RYGB between January 2008 and June 2010 with at least one medical follow-up visit. The dependent variable was the Bariatric Analysis and Reporting Outcome System (BAROS) score, which combines clinical (%Excess weight loss, co-morbidity resolution) and quality of life outcomes in one categorical variable (failure/fair/good/very good/excellent). Independent variable was adherence to medical follow-up visits, adjusted for potential covariates. Univariate and multivariate analysis (by linear regression) were performed at 12 and 24 months after surgery. RESULTS: A total of 5311 patients were part of the study cohort (85.1% female, age at surgery 38.5 ± 10.1 years, 61.9% with at least one obesity-related co-morbidity). At 12-months, data from 1,035 patients were available, with 96.1% of patients scoring good or better at BAROS. Adherence to follow-up visits was not significantly associated with BAROS at 1 year (coefficient -0.046, 95%CI -0.218 to 0.126). At 24-months, data from 319 patients were available, with 92.2% scoring good or better at BAROS. Adherence to follow-up visits was significantly associated with a better BAROS score (coefficient 1.66, 95%CI 1.13-2.18). In multivariate linear regression, presence of co-morbidity is associated with higher BAROS scores at 24 months (p<0.001), and adherence to follow-up visits acts as an effect modifier of this association, with a positive effect in the sub-group with co-morbidity. CONCLUSIONS: Patients with obesity related co-morbidity seems to benefit more from RYGB at 24 months post-surgery. Adherence to medical appointments is an important variable to drive better outcomes in this population.