The main aim of this study was to evaluate the effects of a 10-week sensomotor exercise programme on body balance and agility in a group of adolescent athletes. Initially, 120 adolescent football players were included in the study. In the final analysis, 90 athletes aged 10-17 years participated. The study was designed as a single-blinded, randomised controlled trial. Healthy athletes who met the inclusion criteria were randomly divided into two comparative groups: experimental and control groups. Sensomotor exercises were conducted twice weekly for 10 weeks in the experimental group. The adolescent footballers were subjected to the following tests: a COP (Centre of Pressure) test on a stabilometric platform, a Y balance test (Y-BT), and an agility test. The experimental group showed improvement with respect to the following variables: COP-based path length, with eyes open, for 30 s duration-improved by 5.3 cm (mean: 20.0; 95% CI 15.3-24.8); area, with eyes open, for 30 s duration-improved by 1 cm(2) (mean 2.1; 95% CI 0.6-3.5); area, with eyes closed, for 30 s duration-improved by 0.4 cm(2) (mean 2.2; 95% CI 1.6-2.8). The Y-BT was significantly improved in terms of the final score for the following variables: left leg anterior by 2.1% (mean 73.1; 95% CI 70.7-75.2); right leg posterolateral by 3.8% (mean 112.3; 95% CI 109.3-115.3); right and left leg posteromedial by 5.6% (mean 111.7; 95% CI 108.6-114.9) and 5.7% (mean 112.3; 95% CI 109.7-115.1), respectively; medium posterolateral by 3.2% (mean 111.8; 95% CI 109.0-114.7); medium posteromedial by 6.0% (mean 112.0; 95% CI 109.2-115.0); and Y total score by 3.5% (mean 98.8; 95% CI 96.6-100.9). The agility test in the experimental group was improved by 1.6 s (mean 13.2; 95% CI 12.6-14.0). A 10-week programme of additional sensomotor exercises improved selected parameters determining balance and agility in the young football players.