Although studies in several populations have provided support for Penn State Worry Questionnaire (PSQW) reliability and validity, factor analysis studies carried out on different populations show divergent results. The aim of this article is to contribute with the cross-cultural literature on PSWQ. This report describes two studies examining the psychometric characteristics of a revised Argentinean version of the PSWQ. In the first study, items of original PSWQ were translated into Spanish and then back-translated into English. Then, in order to examine its reliability and factorial structure, the instrument was completed by 400 community participants. The second study included two groups of participants as follows: patients with generalized anxiety disorder (GAD), and patients with other anxiety disorders (AC). Results revealed appropriated test-retest reliability over a four-week period, high internal consistency, and good convergent and discriminant validity for PSWQ. In concordance with some results reported in previous studies, a single factorial structure was confirmed for the Argentinean version of PSWQ. By the other hand, a receiver operating characteristic analysis was made to evaluate the ability of PSWQ to discriminate GAD from individuals with others anxiety disorders. A total score of 63 simultaneously optimized sensitivity and specificity in discriminating GAD patients from patients with others anxiety disorders.