The purpose of this study was to compare several different measures of physician–patient communication. We compared data derived from different measures of three communication behaviors, patient participation, physician information giving, and physician participatory decision-making (PDM) style, from 83 outpatient visits to oncology or thoracic surgery clinics for pulmonary nodules or lung cancer. Communication was measured with rating scales completed by patients and physicians after the consultation and by two different groups of external observers who used rating scales or coded the frequency of communication behaviors, respectively, after listening to an audio recording of the consultation. Measures were compared using Pearson’s correlations. Correlations of patients’ and physicians’ ratings of patient participation (r = .04) and physician PDM style (r = .03) were low and not significant (p > .0083, Bonferroni-adjusted). Correlations of observers’ ratings with patients’ or physicians’ ratings for patient participation and physician PDM style were moderate or low (r = .15, .27, .07, and .01, respectively) but were not statistically significant (p > .0083, Bonferroni-adjusted). Correlations between observers’ ratings and frequency measures were .31, .52, and .63 and were statistically significant with p values .005, <.0001, and <.0001, respectively, for PDM style, information giving, and patient participation. Our findings highlight the potential for using observers’ ratings as an alternate measure of communication to more labor intensive frequency measures.