The authors evaluated associations of patient and clinician characteristics with high-quality communication among patients with chronic obstructive pulmonary disease. Using a cross-sectional analysis from patients with chronic obstructive pulmonary disease enrolled in a clinical trial, the authors evaluated the association of patient and clinician characteristics with patient-reported communication quality. The authors measured these associations using general estimating equations and adjusted odds ratios for best imagined communication quality. Most patient and clinician characteristics, including age, race/ethnicity, mental health attributes, and clinician specialty, were not associated with communication quality. Patient-reported clinician expertise (OR = 2.10, 95% CI [1.52, 2.88], p < .001) was associated with increased communication quality, while the patient not being married was associated with decreased quality (OR = 0.52, 95% CI [0.27, 0.99], p = .047). Only one modifiable characteristic, patient-reported clinician expertise, was associated with best imagined communication quality. This characteristic may be important to include as a potential intermediate outcome in future communication intervention studies. Predictors and outcomes of communication quality are not uniform across patient populations and settings. To maximize the effectiveness of communication interventions, it is important to have a thorough understanding of which patient, clinician, and system factors are associated with communication quality.