The main focus of palliative care services is to improve patients' quality of life (QOL). The potential value of assessment of QOL in palliative care is being increasingly recognized. The McGill Quality of Life questionnaire (MQOL) is designed specifically for palliative care patients, but its cross-cultural validity needs to be determined before it can be applied in populations of different cultures and ethnic groups. The cross-cultural validity of MQOL was investigated using a translated and modified version in Chinese--the MQOL-HK--in 462 palliative care patients in Hong Kong. Results show that the MQOL-HK is acceptable, valid and reliable. There is good acceptability, construct validity, convergent and divergent validity, test-retest and inter-rater reliability. Our study confirms that QOL does have cross-culturally robust constructs. Principal components analysis shows that the domains of physical, psychological, existential and support are all relevant and applicable in Chinese culture. Multiple regression analysis reveals that existential domain is the most important domain in predicting overall QOL. 'Face', eating and sex are additional facets of QOL that also need to be considered. The worst physical symptom on admission is the item of QOL with the lowest score, which need more care and attention by palliative care workers. A cross-culturally validated QOL instrument cannot just help ensure an accurate evaluation of profile, determinants, and changes of QOL, but is also a valuable asset for future comparison and evaluation of palliative care services and interventions across the world.