Background <p>Effective clinician-patient communication is essential for delivering quality end-of-life care. However, there are no validated measures to assess the quality of end-of-life communication for Chinese patients.</p> Methods <p>This study aims to cross-culturally adapt and validate the patient-reported Quality of Communication Questionnaire (QOC) for Chinese speaking patients. The QOC was translated and adapted using a standardized methodology consisting of forward translations, backward translations, expert panel review, and testing with patients. We conducted a cross-sectional study to perform principal component, content validity, internal consistency, convergent and discriminant validity analyses of the 16-item Chinese QOC (C-QOC). Subjects were Chinese-speaking advanced cancer (<i>n</i> = 82) and advanced chronic kidney disease (<i>n</i> = 68) patients attending outpatient clinics in five hospitals or receiving home-based palliative care in Hong Kong.</p> Results <p>The content validity of the C-QOC was established by an expert panel. The C-QOC has a 3-component structure (general communication skills, communication about illness trajectory, and end-of-life care planning subscales) and demonstrated good internal consistency (Cronbach’s α = 0.88; subscales 0.84–0.90). Convergent validity was supported by positive association between C-QOC score and overall clinician communication quality (<i>r</i> = 0.47, <i>p</i> &lt; 0.001) and clinician comfort in discussing dying (<i>r</i> = 0.63, <i>p</i> &lt; 0.001). Discriminant validity was demonstrated by the stronger association between overall clinician communication quality and general communication skills, compared to the other two subscales.</p> Conclusions <p>The C-QOC is a valid, reliable, and culturally relevant instrument for evaluating the quality of clinician end-of-life care communication by Chinese patients with advanced cancer and chronic kidney disease.</p>