Body composition has been associated with better performance in military populations. However, there is no consensus about the most suitable body composition values for army paratroopers. To analyze body composition differences among the type of specialty, age group, and gender of army paratroopers, for a better improvement of their operability. 104 paratroopers of the Spanish Army were analyzed. Anthropometric and morphological data were analysed throw an In-Body720. There was a significant effect of age on intracellular water. Older soldiers had lower values of intracellular water, protein, and skeletal muscle mass than middle-aged soldiers. No significant differences (P ≤ 0.05) for the effect of the kind of work and age together or taken separately. Men had significantly higher values than women for height, weight, extracellular water, protein, fat-free mass, and skeletal muscle mass, and significantly lower values for the percentage of body fat, while no differences were found for body fat mass and body mass index. We conclude that paratroopers’ body composition depends on age in skeletal muscle mass, intracellular water, and protein. For better unit readiness, soldiers must be monitored to analyze the effect of training and nutrition habits on their body composition.