OBJECTIVE: King's Health Questionnaire (KHQ) is a self-administered, 32-item, 8-domain, urinary incontinence-specific quality of life (QOL) instrument. A critical appraisal of the literature was conducted to assess its psychometric properties across all available language versions. METHODS: Computer searches limited to English language and Humans were conducted using PubMed with keywords "KHQ" or "king's health questionnaire". When articles ascertained through these searches referenced additional citations, we retrieved them. Exclusion criteria were: review articles, no information on psychometric properties, related to short-form KHQ, or KHQ was used to validate other QOL measures. RESULTS: We found 11 articles that met the inclusion criteria. Item generation included data from over 1,100 patients, inputs from clinicians, and items from existing instruments. Eight articles were on English version-KHQ, and 3 were on Portuguese-, German-, and Japanese-KHQ (one article per language). Cronbach's ¦Á was °Ý0.7 for English- and German-KHQ. The range of ¦Á was wider for Portuguese-, and Japanese-KHQ (¦Á = 0.47-0.88 and 0.63-0.90, respectively). English-KHQ had a high test-retest reliability across all 8 domains (Spearman's ¦Ñ = 0.80-0.96). KHQ had face and content validity. KHQ was used in multiple clinical trials and it underwent a systematic translation process involving forward translation, backward translation, and cultural adaptation. Correlation coefficients between KHQ and SF-36 domains were (-0.32 to -0.73) and (-0.26 to -0.63) for English- and German-KHQ. Internal responsiveness was shown in Portuguese-KHQ with the mean standardized response mean ranging -0.54 to -1.61. Using both distribution- and anchor-based methods, a change from baseline of at least 5 points on KHQ domains meant a minimal important difference. CONCLUSION: The KHQ is reliable and has good face and content validity, responsiveness, and interpretability. Construct validity was variable across different language versions and KHQ domains. Thus, we recommend additional research on construct validity, especially in European populations.