Nonattachment is defined as a flexible and balanced way of relating to one’s experiences without clinging to or suppressing them. Nonattachment has a long history in Buddhist writings and has recently emerged in modern psychological research. The growing popularity of nonattachment can be attributed, in part, to the development of an empirical scale to measure it. The Nonattachment Scale, created by Sahdra and colleagues in 2010, is a 30-item scale designed to measure nonattachment as it might manifest in one’s everyday life. Nine experts belonging to three major Buddhist traditions reviewed 135 candidate nonattachment items in terms of fit with their understanding of nonattachment. Seventy-five items received consistently high ratings across the different traditions and were used in all subsequent scale reduction analyses. The resulting 30-item nonattachment measure has been found to be reliable and has good criterion and discriminant validity. The Nonattachment Scale has also been translated into Spanish and Chinese for use with non-English speaking populations. In addition, two short forms of the Nonattachment Scale have been developed: the NAS-SF and the NAS-7 (8 and 7 items, respectively). Their validation and psychometric properties are discussed, and a brief comparison of the scales is provided. This chapter also provides details of how to use the Nonattachment Scale in research.