PurposeSimple Triage and Rapid Treatment (START) is a unique triage system used by prehospital providers during disasters to quickly categorize and prioritize patient care according to severity. This study aims at evaluating knowledge about the START triage system among field emergency medical service (EMS) personnel working at the Saudi Red Crescent Authority (SRCA) in the stations of the city of Riyadh.Design/methodology/approachThis is a cross-sectional study that examined data collected from August 2019 to January 2020. The statistical population is from all field EMS personnel working in the SRCA located in Riyadh, Saudi Arabia. Using simple random sampling, 239 field EMS personnel were assessed, and 235 completed the study (98.3% response rate). Data were collected electronically using demographics and 15 multiple choice emergency scenarios based on the START protocol.FindingsThe mean correct score is 8.21 ± 3.36 out of 15 questions of triage knowledge (score of 0–15 points), indicating that those respondents have moderate knowledge levels on the START triage tool. Physicians and paramedics have higher mean scores (10.13 ± 3.42 and 9.07 ± 3.22, respectively), which are significantly higher than emergency medical technicians and nurses (7.25 ± 3.15 and 5.63 ± 2.72, respectively; p < 0.05). The providers who attended the training course had higher mean scores (p < 0.05).Originality/valueBased on the results of the study, field EMS personnel did not reflect full knowledge of START triage tool. An interdisciplinary approach that adopts reinforcement education and periodical training courses is highly recommended to improve the respondents' performance and productivity. Moreover, there was a noticeable correlation between performance of respondents on the one hand and their education levels and prior training on the other hand.