ABSTRACT Introduction Concussion is a common brain injury that has significant effects on multiple functional domains in children. However, limited research exists on the relationship between concussion severity and functional performance in this population. This study aimed to examine the relationship between the severity of concussion symptoms and children’s balance and functional performance. Methods This cross-sectional study recruited 23 children (9 males and 14 females; mean age 13.9 ± 2.2 years) with clinically diagnosed concussions from a tertiary balance center in 2016. Participants underwent clinical and functional evaluations by specialized physical therapists. Symptom severity was assessed using the Post-Concussion Symptom Scale (PCSS), while functional performance was measured using the Functional Gait Assessment (FGA). Results There was a trend suggesting a negative correlation between symptom severity (PCSS) and functional performance (FGA), indicating potentially better performance in individuals with milder symptoms. However, this trend was not significant (rs (21) = –.072, p = 0.744). Furthermore, no significant correlation was found between FGA scores and the severity of individual symptoms. Conclusion The findings suggest that concussion symptom severity may not be directly related to functional performance in children. Therefore, it is crucial to incorporate functional performance measures alongside symptom assessment for comprehensive concussion management.