Objective: Severe obesity is a public health issue. Treatment includes nutritional plans, physical exercise, pharmacotherapy, and bariatric surgery. The objective of this study was to describe the clinical and demographic characteristics of patients who underwent bariatric surgery at a hospital in Medellín, Colombia between January and December of 2010. Methods: Descriptive study which included 525 patients. Information from medical records was obtained and demographic, clinical, and surgical variables were considered. Variables of interest were described and exploratory analysis was conducted using MannWhitney U test and chi-square test; statistical significance was set at p<0.05. Results: Women made up 80.6% of the population, where the median age was 39 years, interquartile range (31-49). The most frequent comorbidity was hypertension (56%), followed by dyslipidemia (44.8%). Patients who underwent bypass surgery had a median body mass index of 41.7 kg/m2, while patients who underwent sleeve gastrectomy had a median body mass index of 37.4 kg/m2, (p < 0.0001). In 36% of patients, at least one psychiatric disorder was present, the most frequent of which was major depression (13.5%). In patients who underwent bypass surgery, the most frequent 30-day postoperative complication was digestive bleeding in 1.7% of cases. No complications presented in gastric sleeve patients. Conclusions: Of the patients, 56% presented at least one medical comorbidity, while 36% had at least one psychiatric comorbidity. This situation warrants a multidisciplinary therapeutic intervention. There was no post-operative mortality 30 days after surgery  
