Although the importance of recognizing posttraumatic stress disorder (PTSD) in primary care has been well-established, routine screening for PTSD remains unfeasible for many primary care clinics because of the length of the available screening instruments. Thus, the purpose of this work was to develop and validate a brief screening tool for PTSD. In Study 1, four short forms of the PTSD Checklist-civilian version were identified that captured a majority of the variance in the measure. In Study 2, the performance of these short forms was evaluated in a separate sample of primary care patients. We found that both two-item and six-item versions have adequate psychometric properties for screening purposes and suggest that the selection of one version over the other depends on the specific needs of each primary care clinic.