This study aimed to translate, culturally adapt, and psychometrically validate the PROMIS Anxiety Short Form 8a item bank into Arabic for the general population of Saudi Arabia. The PROMIS Anxiety Short Form was translated according to the FACIT group method. Second, psychometric validation was conducted on a convenience sample of 322 participants (mean age, 26 ± 10.4 years; predominantly female) from the general population in Saudi Arabia. Rasch analysis (Winsteps® version 5.6.1) was used to examine category functioning, item fit, the person separation index, item difficulty, unidimensionality, and local dependency. Translation and cultural adaptation demonstrated that most of the items were culturally suitable and conveyed the same underlying concepts as the original scale. The five response categories of the scale satisfied the category functioning criteria, and all items fit the underlying construct, with the exception of one item that demonstrated a misfit. The item difficulty demonstrated poor targeting for the sample population; however, the person separation index and reliability were good (2.67 and 0.88, respectively) and no local dependency was noted. The Arabic translation of PROMIS-A SF8a demonstrated good structural validity and psychometrics, making it a valuable tool for screening anxiety in Arabic-speaking populations. The application of this outcome measure shows promise for healthcare professionals and patients alike, as it contributes to the provision of high-quality care and formulation of appropriate treatment plans.