The present study examined the usefulness of the Penn State Worry Questionnaire (PSWQ) as a means of screening for generalized anxiety disorder (GAD). Using receiver operating characteristic analyses, the accuracy of the PSWQ in screening for GAD was examined in both clinical and analogue diagnosed GAD samples. Given high comorbidity between GAD and other emotional disorders, we also investigated the usefulness of the PSWQ in selecting non-cases of GAD that were also free of PTSD, social phobia, or depression versus non-cases of GAD that met criteria for one of these conditions. The overall usefulness of the PSWQ as a screening device is discussed.