[Introduction]: Isolation of people needs significant support, potentially impacting their mental well-being for future assignments. [Objective]: This study aimed to examine whether the military institution or other factors were associated with changes in the mental health of Peruvian navy and army personnel in Antarctica. [Methods]: The exploratory study employed a prospective cohort design, conducting surveys at two different points during the trip. Various factors such as stress, anxiety, depression (measured using DASS-21), and post-traumatic stress (measured using SPRINT-E) were assessed, alongside other variables. [Results]: The outcomes indicated noteworthy changes in the participants’ scores. Specifically, stress scores increased among navy personnel but decreased in the army. Moreover, anxiety scores decreased among those with previous trips and increased among those without. ...