The Quality of Communication Questionnaire (QoC) was culturally adapted for Brazil due to its importance and use in several studies and different scenarios. The objective of this study was to evaluate the validity evidence of the Brazilian version of the QoC. A validation study was carried out involving 253 patients admitted to five public hospitals in Southern Brazil. Data were analyzed using descriptive analysis, Cronbach's alpha (α) to assess internal consistency, exploratory factor analysis, and goodness-of-fit index. One hundred and three patients were in intensive care (IC), and 150 were in palliative care (PC). The participants’ mean age was 51 years (SD = 14.2). QoC,and its general communication subscale, and end-of-life communication subscale means were 5.5 (SD = 1.6), 8.8 (SD = 1.5), and 5.5 (SD = 1.6) respectively. Among patients in IC, QoC Cronbach’s alpha was .75, and .84 in the general communication subscale and .51 in the end-of-life communication subscale. Among patients in PC, QoC Cronbach’s alpha was .83, and .88 in the general communication subscale, and .71 in the end-of-life communication subscale. The root mean square error of approximation was .07 (90% CI: .04 – .08); Tucker-Lewis index was .97 (95% CI: .95 – .98); comparative fit index was .98 (95% CI: .97 – .99), and χ2/df ratio was 1.33 (χ2[53] = 70.858, p = .05). The authors conclude that the general communication subscale of QoC Brazilian version has good validity evidence for patients in IC and PC, whereas the end-of-life communication subscale is only valid for patient in PC.