Aims: The Revised Geneva Score (RGS), a standardized Clinical Prediction Rule for Pulmonary Embolism (PE), was recently developed. We have measured its predictive accuracy, performing an external retrospective validation in a cohort of Emergency Department (ED) patients, filtered by symptomatology and not by clinical suspicion, to allow its use in nursing practice.Methods: The clinical probability of PE was assessed in 1013 consecutive patients with symptoms of “chest pain” or “shortness of breath/dyspnea”, whose clinical records were obtained during a two months period, in an Italian ED. The accuracy of RGS was analyzed by the Receiver Operating Characteristic (ROC) analyses; the OR was evaluated with an analysis of the risk raw score.Results: The overall prevalence of PE was 1.09%. The prevalences of PE in the three probability categories were similar and not statistically significant. The Area under the Curve was 0.6373 (CI 0.4336-0.8409). However, the NPV was 0.993 (95% CI 0.981-0.998) and the mean score of risk was 3.36 for the 1002 not affected by PE and 5.73 for the 11 subjects with Pulmonary Embolism (p 0.0003), by exclusively assessing it on the raw score obtained.Conclusions: This study suggests that the performance of the RGS, modified in order to be applied to a nursing emergency approach, gives good results in NPV; it should be also tested to assess the embolic risk by a dichotomous numerical score (rule-in/rule-out), that should be used to supplement rather than as a substitute for clinical judgement.