Introduction: The South African Triage Scale (SATS), a novel triage system for Emergency Centres, was initially proposed in 2006. The system incorporates an adapted version of the Modified Early Warning Score (MEWS). Methods: A prospective study was conducted to evaluate the use of the MEWS as a triage tool in EC settings in the Western Cape, South Africa. A total of 1867 cases were prospectively assessed. The MEWS was correlated with Emergency Centre outcome Results: The data show clear potential for use of the MEWS as a triage instrument for medical patients. Its use for trauma cases is more limited. Conclusion: The MEWS in its un-adapted form is unsuitable as a unified triage scoring system for both medical and trauma cases in Emergency Centres.