ABSTRACT Introduction: Physical activity should be a fundamental part of health promotion programs. However, its performance can expose the individual to risk of injury, which makes it necessary to adopt preventive measures such as warm-up (WU) in order to minimize risks and/or contribute to better functional performance. Objective: The purpose of this study was to analyze the acute effect of different warm-up times on flexibility, balance, and functional performance in physically active individuals. Method: Thirty two healthy men, who exercise regularly at least three times a week, were randomly assigned to one of four groups (n=8): G0 (without WU), G5 (WU for 5 min), G10 (WU for 10 min), and G15 (WU for 15 min). The subjects were assessed before and after the intervention on the following variables: flexibility of the rectus femoris (RF) and hamstrings (HM) muscles, body balance with open and close eyes and functional performance through triple horizontal jump (THJ) and shuttle run (SR) tests. The WU was carried out on a treadmill between 70% and 80% estimated maximum heart rate for age. Results: There were no significant differences in flexibility and balance in intra and intergroup comparisons (p>0.05). However, there was a significant improvement in functional performance only in G10 in the intragroup comparison for THJ variables (5.88±0.55 to 6.23±0.66; p=0.0051) and SR variables (4.72±0.13 to 4.61±0.13; p=0.0194) variables. Conclusion: Warm-up for 10 minutes seems to improve functional performance in active individuals, and may be a viable alternative for injury preventions.