The aim of this study is to analyze the relationship between health-related quality of life (QoL), disability, and degree of obesity. Adult obese patients (BMI greater than 30) were consecutively enrolled in this cross-sectional observational study. The WHO Disability Assessment Schedule (WHO-DAS II) and the short version of the impact of weight on QoL (IWQoL-Lite) were administered. Spearman's rank correlation analysis was performed. A "P" value of less than 0.01 was used to set the statistical significance. A total of 117 patients (mean age: 47.4 years, mean BMI: 43.7) were enrolled. Correlations between WHO-DAS II and IWQoL-Lite were between 0.21 and 0.78. BMI between 0.19 and 0.26 correlated with WHO-DAS II and BMI between 0.23 and 0.49 correlated with IWQoL-Lite. In conclusion, low/moderate correlations between BMI index, disability, and health-related QoL measures, and a low association between the two outcome measures are reported, supporting the idea that they underline different and not transposable dimensions.