AIMS: To assess the practical implementation of international guidelines and their impact on syncope management in a 500-bed general hospital. PATIENTS AND METHODS: Three groups of 63 consecutive patients admitted for syncope to the emergency care unit (ECU) were studied: group 1, before the guidelines delivered to the practitioners, group 2 immediately after the diffusion of guidelines and group 3, one year later. The study evaluates the mean duration of stay (MDS) and the relevance of the diagnostic strategy. RESULTS: In group 1 compared to group 2, MDS were respectively 6.8±5.5 and 5.4±2.8 days (P=0.07) and the unexplained syncope number respectively 22% and 24% (P=0.8). The search of orthostatic hypotension became more systematic (13% versus 86% in group 1 and 2 respectively, P<0.001). The agreement (kappa coefficient) between initial and final diagnostic increased in 0.34 to 0.44. One year later MDS in group 3 was 7.1±4.7 days (P=0.8 versus group 1 and P=0.015 versus group 2) with only 6.3% systematic search for orthostatic hypotension (P<0.001). CONCLUSIONS: Guidelines optimize the syncope management in the ECU and the agreement between the emergency and discharge diagnostic without change of unexplained syncope and. MDS tend to be shorter when guidelines are actively implemented. Nevertheless, the positive impact of guidelines implementation is of limited duration.