Objectives: The aim of the research is to explore differences in the quality of the ABCDE approach implementation in regard to the composition of the team of emergency medical services which conducts the ABCDE approach with patients with a red or yellow criterion of urgency. Study design: A retrospective study. Examinees and methods: A retrospective study has been conducted among 392 patients who have been cared for by teams of emergency medical service, in the period from the 1st January 2015. to the 31st December 2015. The research was conducted by collecting data from findings of the patients entered in the e – Hitna computer program in the Department of Emergency Medicine of Brod-Posavina County. Results: By statistical analysis of the total number of patients, we concluded that the T1 team has done a significantly more frequent good quality and poor quality assessment, while the T2 team has done a significantly frequent poor quality assessment. With patients with a red criterion emergency, the T2 team has done a significantly frequent less quality assessment with 74 (66,4%) patients and poor quality assessment with 30 (27%) patients, while the T1 team has done significantly more quality assessment with 47 (29,9%) patients. With the yellow urgency criterion, the T1 team has made a significantly more frequent high quality assessment with 11 (15,1%) patients, and less quality assessment with 56 (76,7%) patients, compared to the T2 team, which makes significantly more frequent poor quality assessment, i.e. out of 26 (21%) patients with a poor quality assessment, 20 of them (39,2%) has been done by the T2 team. Conclusion: Research has shown that the composition of the teams of emergency medical services significantly affects the quality of the implementation of the ABCDE approach.