The World Health Organization (WHO) initiated a cross-cultural project on the development of the WHOQOL-100 questionnaire in 1991 and finished it in 1995. Later, the questionnaire was simplified to the WHOQOL-BREF containing 26 items. The long form of the questionnaire contains 100(culturally comparable) generic core questions. However, it allows each nation/culture to add culture-specific questions. We started to develop the questionnaire-Taiwan version in 1997. This paper briefly introduces the developme nt of the WHOQOL-Taiwan Versions. The procedures of translating the questionnaire, selecting the appropriate scale descriptors, and proposing suitable culture-specific items were seriously designed. We collected the data on 1068 subjects from 17 hospitals in Taiwan to conduct reliability and validity analyses. The results showed that the internal consistency (Cronbach's a) and the test-retest reliability coefficients of the questionnaire were 0.97 and 0.86 respectively; the indices of content validity and concurrence validity achieved statistically significant (p < .01); most of the items could discriminate between healthy and unhealthy subjects; Facet-G score (for measuring general QOL and health) was well predicted by the six domain scores and the explained variance was about 64.2%. Moreover, four-factor model (i.e., physical capacity, psychological, social relationship, and environment ) was the most plausible model. Based on our data analysis, the psychometric properties of the questionnaire for Taiwan version were convincing and were comparable to the global study.