Background: Patients with heart failure (HF) often have multiple chronic conditions that may impact health-related quality of life (HRQOL) despite HF therapy. We sought to determine the association between noncardiac comorbidities and HRQOL in ambulatory patients with advanced HF. Methods: Baseline data from 373 subjects in REVIVAL (Registry Evaluation of Vital Information for Ventricular Assist Devices in Ambulatory Life) were analyzed using multivariable general linear models to evaluate the relationship between comorbidities and HRQOL (EuroQol Visual Analogue Scale, EQ-5D-3L Index Score, and Kansas City Cardiomyopathy Questionnaire). The primary independent variables were a comorbidity index (sum of 14 noncardiac conditions), a residual comorbidity index (without depression), and depression alone. The median (25th to 75th percentile) number of comorbidities was 3 (2-4). Results: Increasing comorbidity burden was associated with a reduction in generic (EQ-5D Index, P=0.005) and HF-specific (Kansas City Cardiomyopathy Questionnaire, P=0.001) HRQOL. The residual comorbidity index was not associated with HRQOL when depression included in the model independently, while depression was associated with HRQOL across all measures. Participants with depression (versus without) scored on average 13 points (95% CI, 8-17) lower on the EuroQol Visual Analogue Scale, 0.15 points (95% CI, 0.12-0.18) lower on the EQ-5D Index, and 24.9 points (95% CI, 21.2-28.5) lower on the Kansas City Cardiomyopathy Questionnaire overall summary score. Conclusions: While noncardiac comorbidities were prevalent in ambulatory advanced HF patients, only depression was associated with decreased generic and HF-specific HRQOL. Other than depression, the presence of noncardiac comorbidities should not impact expected gains in HRQOL following ventricular assist device implantation, provided the conditions are not a contraindication to implant. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01369407.