OBJECTIVE: To compare validity indices of the King-Devick (KD) test and Sport Concussion Assessment Tool 5 (SCAT5) for traumatic events in MMA, and to determine if perfusion events (alterations in consciousness as the result of choke holds) cause similar changes in KD/SCAT5 scores. DESIGN: A prospective cohort study in MMA fighters who completed KD and SCAT5 assessments before and after a match. Outcomes were categorized as non-event, traumatic event, or perfusion event. KD/SCAT5 changes were compared between all athletes. PARTICIPANTS: One hundred forty MMA athletes (7 women, 133 men), mean age=27.1 ± 4.9 years. INTERVENTION: N/A. MAIN OUTCOME MEASURES: King-Devick (KD) test and Sport Concussion Assessment Tool 5 (SCAT5). RESULTS: Among the 140 athletes, 19 sustained traumatic and 15 perfusion events. Testing provided sensitivities/specificities of 21.05%/93.39% (KD) and 77.78%/52.99% (SCAT5) in detecting a traumatic event. KD and SCAT5 Symptom Severity scores differed between athletes with and without traumatic events (P=.041 and .014). KD and SCAT5 Symptoms Score changes were observed between athletes with and without traumatic events (P=.023 and .042). Neither KD nor SCAT5 differed significantly between athletes with and without perfusion events. CONCLUSIONS: The KD test provides high specificity and the SCAT5 demonstrates reasonable sensitivity when detecting a traumatic event. Of the SCAT5, symptoms-related scores may most effectively identify a traumatic event. A traumatic event may cause KD/SCAT5 changes similar to a concussion, while perfusion events did not.