Health-related quality of life (HRQOL) is impaired in severely obese individuals presenting for bariatric surgery. Little is known about the relationship between cardiorespiratory fitness (CRF) and HRQOL in these individuals. We hypothesized that better HRQOL would be reported by those with higher CRF. In 326 gastric bypass patients (mean BMI = 46.5 ± 7.0; mean age=40.9 ± 10.1; 83.4% female), pre-surgical CRF was quantified as duration (minutes) of a submaximal treadmill test to 80% of age-predicted maximal heart rate (MHR). Patients completed both a general measure of HRQOL [the Medical Outcome Short Form 36 (SF-36)] and a weight-specific measure of HRQOL [Impact of Weight on Quality of Life--Lite]. Mean HRQOL scores were examined, controlling for age, gender, and BMI. Mean treadmill duration was 9.9 ± 3.1 min, and percent age-predicted MHR was 81.2 ± 3.0%. Higher cardiorespiratory fitness tended to be associated with better physical and weight-specific HRQOL. Adjustment for differences in gender, age, and BMI attenuated the significance of associations between fitness and physical measures from the SF-36, whereas adjustment eliminated significance of associations between fitness and weight-specific HRQOL in most cases. Results suggest that CRF confers some HRQOL benefits in severely obese adults, though these benefits may largely be explained by differences in age, gender, and BMI.