Research on nonattachment has consistently shown that it is conducive to psychological well-being and interpersonal outcomes. However, there is a lack of rapid assessment that can provide valid and reliable measure among individuals with different levels of nonattachment. The present study aimed at developing a short form of the Nonattachment Scale (NAS) under the item response theory framework. Study 1 recruited 1019 participants who were mainly students and they completed the Nonattachment Scale. Based on the item information and item location, eight items were selected that yielded satisfactory internal consistency and test information. In study 2, 393 college students were recruited and the criterion validity of the 8-item Nonattachment Scale-Short Form (NAS-SF) was examined. Results showed that the 8-item NAS-SF was correlated with mindfulness ($r$ = .54), mental well-being measures ($r$s = .46 to .54), psychological distress measures ($r$s = −.48 to −.57), and social/interpersonal measures ($r$s = .24 to .41). Findings suggested that the 8-item NAS-SF is a reliable and valid measure that can be applied to individuals with different levels of nonattachment in an efficient way.