This cross-sectional study explored the relationship between pain intensity, injury incidence, and sociodemographic factors in 120 high school athletes (mean age 16.78±0.91) participating in various sports. The aims of this study are to examine the correlation between factors and Verbal Rating Scale (VRS) for pain intensity, to investigate the correlation between sport types and injured region, and to explore the correlation between injured regions and VRS during training and game competition. Using VRS, we found 64 (53.3%) participants experienced pain during training, with varying degrees of intensity. Chi-square analysis revealed a significant association between VRS scores and school grade (p = 0.044) and cool-down practices (p = 0.037). However, no significant associations were found with gender, age, or sport type. In game competition, 29 (24.2%) participants reported experiencing pain. Here, there was no significant association between VRS and any considered variables. Lower limb injuries were predominant (n = 64), particularly to the knee (n = 23) and ankle/foot (n = 18). Certain sports, like Athletics, Karate-Do, Football, and Western Boxing, demonstrated multiple injury sites, whereas Thai boxing was associated primarily with ankle and foot injuries. Pain intensity varied by injury location, with the highest ’worst pain’ reported for elbow injuries during training and knee injuries during competition. Significant associations were found between injured region and pain intensity level during both training and competition (p<0.001). Our findings highlight the need for injury prevention strategies and pain management among high school athletes, emphasizing proper cool-down activities. Further research is warranted to confirm these findings and explore underlying mechanisms.