The Anxiety Sensitivity Index-3 (ASI-3; Taylor et al., 2007) is a self-report assessment of anxiety sensitivity, reflecting one’s tendency to misinterpret the meaning of anxiety-relevant sensations. Despite this construct being related to a wide array of clinically-significant smoking maintenance and relapse processes, the psychometric properties of scores on the ASI-3 have not yet been investigated for use among smokers. Therefore, the current study aimed to test the psychometric properties of the scores on the ASI-3 in a sample of cigarette smokers. Participants were treatment-seeking daily smokers who completed the ASI-3 at a pre-cessation visit (Time 1: n = 464) and three-months post-cessation attempt (Time 2: n = 137). Confirmatory factor analyses results of the scores on ASI-3 at Time 1 and Time 2 revealed the hypothesized three-factor model, including physical, social, and cognitive concerns. Additionally, the ASI-3 factor scores evidenced factor stability, test-retest reliability, internal consistency, convergent, discriminant, and predictive validity. The present study provides evidence in support of the validity and reliability of scores on the ASI-3 as a measure of anxiety sensitivity among treatment-seeking cigarette smokers.