Health-related quality of life (HRQoL) is an important measure of illness perception on the part of the patient. The Inflammatory Bowel Disease Questionnaire (IBDQ) is a widely used questionnaire for HRQoL assessment in patients with inflammatory bowel diseases (IBDs). This questionnaire has been adapted and validated into several languages and cultural milieus. The aim of this study is to review the methods used by several adaptation studies for assessing the validity and reliability of the adapted IBDQ. A search was made of the Medline database for relevant articles since 1989. Standard validation criteria were used for including studies for further evaluation. The following aspects of the validation procedure were examined: translation, construct validity, reliability, sensitivity to change, and used statistical methods. Nine validation studies of the IBDQ, in England and in non English-speaking countries (Holland, Spain, Korea, Sweden, Greece, and China) were selected. All studies concluded that the adapted instrument was valid and reliable. Only few modifications were proposed. Two studies recommended the split of the four dimensions of the original questionnaire in five. Assessing HRQoL in patients with IBD is an ever-increasing practice, especially in clinical trials. IBDQ was proven to be valid and reliable in several cultural and linguistic milieus when appropriate validation procedures were applied.