Background: Advance care planning (ACP) facilitates identification and documentation of patients' treatment preferences. Its goal aligns with that of palliative care – optimizing quality of life of seriously ill patients. However, concepts of ACP and palliative care remain poorly recognized in Chinese population. This study aims at exploring barriers to ACP from perspective of seriously ill patients and their family caregivers. Methods: This is a qualitative study conducted in a Palliative Day Care Centre of Hong Kong between October 2016 and July 2017.