Journal ArticleBackground. A history of falls or imbalance may lead to a fear of falling, which may lead to self-imposed avoidance of activity; this avoidance may stimulate a vicious cycle of deconditioning and subsequent falls. Objective. The purpose of this study was to develop a questionnaire that would quantify avoidance behavior due to a fear of falling. Design. This study consisted of 2 parts: questionnaire development and psychometric testing. Questionnaire development involved an expert panel and 39 residents of an assisted living facility. Sixty-three community-dwelling individuals with various health conditions participated in psychometric testing. Method. Questionnaire development included the evaluation of face and content validity and factor analysis of the initial questionnaire. The final result of questionnaire development was the Fear of Falling Avoidance Behavior Questionnaire (FFABQ). In order to determine its psychometric properties, reliability and construct validity were assessed through administration of the FFABQ to participants twice, 1 week apart, and comparison of the FFABQ with other questionnaires related to fear of falling, functional measures of balance and mobility, and daily activity levels using an activity monitor. Results. The FFABQ had good overall test-retest reliability (intraclass correlation coefficient=.812) and was found to differentiate between participants who were considered ?fallers? (ie, at least one fall in the previous year) and those who were considered ?nonfallers.? The FFABQ predicted time spent sitting or lying and endurance. Limitations. A relatively small number of people with a fear of falling were willing to participate. Conclusion. Results from this study offer evidence for the reliability and validity of the FFABQ and support the notion that the FFABQ measures avoidance behavior rather than balance confidence, self-efficacy, or fear