Purpose This pilot observational study aimed at determining the causes of attrition during the Italian Army- Rangers training program identifying possible predictor characteristics. Methods In 103 male recruits (26 ± 2 years) we measured anthropometric and functional characteristics and monitored drop-out date and cause in the first 6 months of the program. The possible association of anthropometric or functional parameters with dropout was evaluated (unpaired t-test, successful vs dropouts). Results Anthropometric (body weight 77 ± 7 Kg, stature 178 ± 7 cm, fat mass 12 ± 3 %) and functional characteristics (2 km-run 448 ± 22 s, number of pull-ups 12 ± 3, number of dips 19 ± 5, number of push-ups in 60 s 41 ± 10, number of sit-ups in 60 s 45 ± 5) were similar to those reported in the literature for special forces in Europe. 42 recruits (41 %) abandoned the program, the main cause of dropout being voluntary withdraw for personal reasons (60 %); 30 % of recruits were excluded from the program for medical reasons; 10 % for technical reasons (e.g. fail of technical exams or physical requirements, discipline issues). Significant differences between successful and dropout groups were detected only in % of body fat (11 ± 3 vs 13 ± 3) and the number of pull-ups (12 ± 3 vs 11 ± 4). Conclusions Ours are the first available data on Italian Army-Ranger trainees. Our data suggest targeting individual motivation, self-efficacy and resilience upon admittance to the program as potential factors affecting dropout for personal reasons. Furthermore, optimal physical preparation practices (including gradual overload and injury prevention strategies) and optimal medical treatment could potentially reduce attrition for medical and technical reasons.