Background: Chronic disease self-management is complex and multidimensional. Optimal performance of self-management behaviors requires support from patient's friends, family, and significant others. The Multi-dimensional Scale of Perceived Social Support (MSPSS) is a 12-item questionnaire used to measure patient's social support from friends, family, and significant others. Objectives: To examine the psychometric properties of the MSPSS in patients with comorbid chronic obstructive pulmonary disease (COPD) and heart failure (HF). Methods: Reliability, factorial validity, and construct validity of the MSPSS were examined using Cronbach's alpha, split-half reliability, factor analysis via principal components analysis and hypothesis testing via multivariate linear regression, respectively. Results: The MSPSS demonstrated excellent internal consistency with Cronbach's alpha consistently above 0.90. Factor analysis yielded a 3-factor solution, with items loading appropriately on the Friend, Family and Significant Other subscales. Conclusion: The MSPSS is a reliable, valid instrument to measure perceived social support in patients with comorbid COPD and HF. (C) 2018 Elsevier Inc. All rights reserved.