Triage is the process of sorting patients based on the level of acuity to ensure the most severely injured and ill patients receive timely care before their condition worsens. The South African Triage Scale (SATS) was developed out of a need for an accurate and objective measure of urgency based on physiological parameters and clinical discriminators that is easily implemented in low resource settings. SATS was introduced in the emergency center (EC) of Komfo Anokye Teaching Hospital (KATH) in January 2010. This study seeks to evaluate the accurate use of the SATS by nurses at KATH. Methods: This cross-sectional study was conducted in the EC at KATH in Kumasi, Ghana. Patients 12 years and over with complete triage information were included in this study. Each component of SATS was calculated (i.e. for heart rate of 41–50, a score of 1 was given) and summed. This score was compared to the original triage score. When scores did not equate, the entire triage record was reviewed by an emergency physician and an advanced practice emergency nurse separately to determine if the triage was appropriate. These reviews were compared and consensus reached. Results: 52 of 903 adult patients (5.8%) were judged to have been mis-triaged by expert review; 49 under-triaged (sent to a zone that corresponded to a lower acuity level than they should have been, based on their vital signs) and 3 over-triaged. Of the 49 patients who were under-triaged, 34 were under-triaged by one category and 7 by two categories. Conclusion: Under-triage is a concern to patient care and safety, and while the under-triage rate of 5.7% in this sample falls within the 5–10% range considered unavoidable by the American College of Surgeons Committee on Trauma, concentrated efforts to regularly train triage nurses to ensure no patients are under-triaged have been undertaken. Overall though, SATS has been implemented successfully in the EC at KATH by triage nurses.