Background: Worry is a central cognitive feature of anxiety and emotional distress, and its accurate assessment is vital for understanding psychological well-being in high-stress societies such as Afghanistan. Objective: The present study aimed to translate and validate the Dari/Farsi version of the of Penn State Worry Questionnaire (PSWQ) in a sample of Afghan students. It employed a descriptive and validation-based approach. Method: The target population of the present research included 254 undergraduate students studying at Herat University, Afghanistan, during the 2024-2025 academic year. Participants were recruited through convenience sampling and responded to an online questionnaire distributed via Qualtrics. To assess temporal stability, a subsample of 40 participants completed the (PSWQ) again after a two-week interval. Data were collected using the PSWQ and the Depression, Anxiety, and Stress Scale (DASS-21). Results: Confirmatory factor analysis supported the unidimensional structure of the PSWQ, indicating an acceptable model fit (chi(2)/df = 2.58, CFI = 0.94, RMSEA = 0.07). The PSWQ scores demonstrated moderate positive correlations with depression, anxiety, and stress as measured by the DASS-21 (r = 0.53, 55, and 0.59, respectively; p < 0.05). In addition, the scale showed satisfactory test-retest reliability over 2 weeks, (r = 0.70, p < 0.05), and high internal consistency (alpha = 0.92). Conclusion: Overall, the findings confirm that the Dari/Farsi version of the PSWQ possesses robust psychometric characteristics. Therefore, it can be confidently utilized as a reliable instrument for research applications as well as for clinical evaluation. Its use is recommended for psychologists and mental health professionals in both diagnostic settings and empirical studies.