Social support has been shown to be an important mediator of health status and survival in chronic illness but little information is available in patients with lung diseases. We used the Social Support Questionnaire (SSQ) to examine the relationships of number of persons (SSQ-N) and satisfaction (SSQ-S) with other measures of health status, treatment changes, and survival in 110 patients with chronic obstructive pulmonary disease (COPD) participating in a randomized, controlled clinical trial of pulmonary rehabilitation (PR). Included in the analyses were measures of lung function (FEV1.0), exercise tolerance (maximum and endurance), symptoms ratings, age, self-efficacy, depression, and gender. At baseline, SSQ-N and SSQ-S were correlated positively with self-efficacy and negatively with depression and self-reported shortness of breath (SOB). SSQ-N was also correlated with disease severity and maximum exercise tolerance (FEV1.0 and VO2 max). Using the Cox Proportional Hazard Model, SSQ-S was significantly related to improved survival up to six years. However, in multivariate analysis, after adjusting for FEV1.0 and SOB which were better predictors of survival, SSQ-S was marginally significant. SSQ-S and survival were computed separately for males and females across treatment groups. SSQ-S was significantly related to mortality for women but not for men. We conclude that social support is related to measures of physical and psychological function in patients with COPD and may influence improvement and survival after pulmonary rehabilitation.