Quality of life (QOL) has become an important component of health. By using the methodology of psychometric theory, we examine the item properties of the WHOQOL-BRIEF. Samejima's graded response model with natural metrics of the logistic response function was fitted. The results showed items with negative natures were less discriminating. Items written in a specific way were more suitable to assess certain subgroups. The national items showed variation in discriminatory power. Questions measuring objective and specific issues performed worse than items assessing general aspects of the QOL.