BackgroundThe PTSD Checklist for DSM-5 (PCL-5) is an internationally widely used self-report questionnaire that can be used to screen for probable diagnosis of posttraumatic stress disorder (PTSD). Information on the psychometric properties of the Dutch PCL-5 is currently lacking.ObjectiveWe aimed to validate the Dutch PCL-5 in a sample of Dutch adults with prior (suspected) serious injury and establish the optimal cut-off for probable PTSD diagnosis herein.MethodsData for the current study were collected as part of a long-term follow-up measurement of the TraumaTIPS cohort, where adults admitted to an emergency department following (suspected) serious injury completed a follow-up measurement 12–15 years post-trauma. Of N = 333 eligible participants, n = 192 (57.7%) consented and completed the PCL-5 alongside self-report instruments measuring depression (QIDS), PTSD (IES-R), and quality of life (WHO-QOL and EQ-6D). In total, n = 185 participants also completed a clinician administered interview for PTSD (CAPS-5). Most participants were men (66%) and on average 54 years old (SD = 12.41). We evaluated the diagnostic utility of the PCL-5 using Youden index and tested reliability and convergent validity.ResultsThe PCL-5 demonstrated excellent diagnostic accuracy with a cut-off point of 16 resulting in an optimal Youden index (0.90) for screening purposes with a high sensitivity (1.00) and specificity (0.90). A cut-off of 22 yielded a slightly lower Youden index (0.84) but better positive predictive value (0.50 instead of 0.33) than the cut-off of 16. A cut-off of 29 resulted in the most accurate prevalence estimates. The PCL-5 showed a high internal consistency (Cronbach’s α = 0.94), excellent inter-item and item-total correlations and good convergent validity (r > .5 for CAPS-5, IES-R and QIDS).ConclusionsThe PCL-5 is a reliable and valid measurement for PTSD symptoms and probable diagnosis and shows excellent screening abilities in Dutch adults with prior (suspected) serious injury, with a lower optimal cut-off compared to previously found in clinical populations. We recommend a cut-off of 22 for screening purposes and a cut-off of 29 for prevalence estimates in Dutch trauma-exposed adults.