The objective of this pilot study was to evaluate the Danish translation of the WHO Quality of Life Questionnaire, the WHOQOL, by means of the psychometric properties of the Danish version. The translation method followed the WHO standard procedures, including forward and backward translation, focus group discussions, and assessment of response choice weighting through visual analogue scales. In the study we evaluated the applicability of the WHOQOL in patients with physical and mental disorders compared with a sample of healthy controls. The WHOQOL was compared with health-related quality of life questionnaire SF36 (Short Form 36). The internal consistency or homogeneity of the Danish WHOQOL was found adequate, and its applicability and its performance in distinguishing between population groups were satisfactory. The abbreviated version of WHOQOL-100, the WHOQOL-BREF, was analysed separately and was also found psychometrically valid. The WHOQOL is a questionnaire that is easy to administer, and it seems applicable for use.