Body composition encompasses a series of variables that are health-related and influence physical condition. Nevertheless, there is little evidence on its effects on the operational capacity of the military. The objective of this study was to relate the body composition, the physical condition and the operational capacity of the Chilean military. Fifty-seven Chilean soldiers (26.9 ± 4.8 years) participated, with operational specialization in infantry. Body composition was evaluated with octopolar bioimpedance, estimating fat-free mass, muscle tissue, and adipose tissue, among other variables. The following physical condition tests were also carried out: 5000 m flat, pull-ups, abdominals and flexibility, as well as four specific tests of specific military operational activities (simulated combat situation). The results showed a percentage of muscle tissue of 45.4 ± 2.9 % (95%CI: 44.6-46.2), while the percentage of adipose tissue was 20.3 ± 4.9 % (95%CI).: 14.7-17.3). Negative correlations of small magnitude were found between race time (5000 m) and muscle tissue (%) (r =-0.275) and positive with adipose tissue (%) (r = 0.294). However, high magnitude correlations were observed between pull-ups and muscle tissue (%) (r = 0.517) and adipose tissue (%) (r =-0.558). Adipose tissue was negatively related to aerobic capacity, upper body endurance strength and abdominal endurance strength, while muscle tissue was positively related to these same varia-bles. No correlations were found between body composition and military operational capacity (p<0.05). It is concluded that body composition and physical condition are not related to military operational capacity in combat situations in infantry specialists, but body composition is related to strength and cardiorespiratory capacity.