Background: Syncope is a transient brief loss of consciousness accompanied with loss of postural tone. Of common places in which people experience syncope, military barracks can be named where training soldiers spend their military courses. The current study aimed to assess etiology and risk factors of syncope among military training soldiers.

Methods: This was a retrospective case-control study conducted on training soldiers of Army-501 hospital in Tehran, Iran, during the years 2017-2018. Cases were consisted of 50 soldiers who experienced syncope during military training, and controls were 150 soldiers who had not experienced syncope during their military training. Demographic data were recorded for cases and controls.

Results: Members of case and control groups were not statistically different regarding age (P = 0.46) and height (P = 0.70). Logistic regression test was performed and considering crude model, weight [odds ratio (OR): 0.94; 95% of confidence interval (95%CI): 0.90-0.98], body mass index (BMI) (OR: 0.72; 95%CI: 0.61-0.85), standing duration (OR: 1.007; 95%CI: 1.00-1.01), history of syncope (OR: 15.47; 95%CI: 4.15-57.60), positive family history of syncope (OR: 5.94; 95%CI: 1.66-21.25), smoking (OR: 3.5; 95%CI: 1.54-7.91), medical problems (OR: 7.97; 95%CI: 1.98-32.17), anxiety (OR: 2.02; 95%CI: 1.13-4.26), stress (OR: 6.68; 95%CI: 3.28-13.57), and depression (OR: 4.25; 95%CI: 2.15-8.39) were detected as significant predictors of syncope occurrence.

Conclusion: Based on the findings of this study, lower BMI, positive history of syncope, smoking, depression, and stress were significant risk factors of syncope occurrence among training soldiers. Higher BMI has protective role in syncope occurrence.