The extreme working and living conditions at Antarctic stations cause numerous psychological changes in expeditioners. However, research on the changes in expeditioners' personality traits is virtually non-existent. Therefore, the present study aims to determine the changes in expeditioners' personality measures during 1 year Antarctic expeditions. This study examined 56 expeditioners working at the Ukrainian Antarctic Akademik Vernadsky station (52 men, 4 women; ages 20–63 years, M = 38.12, SD = 10.01) who participated in five annual expeditions between 2016 and 2021. The Ukrainian adaptations of four measures were used: the Thomas-Kilmann Conflict Mode Instrument, the Eysenck Personality Questionnaire, the Leonhard-Schmieschek Questionnaire and the Leary Interpersonal Checklist. During 1 year Antarctic expeditions, 8 of the 26 indicators used to describe expeditioners' personality measures changed significantly (P < 0.001–0.1). These indicators belonged to three of the four measures used in the study and were assessed as personally unfavourable. They included increased psychoticism and competing, managerial-autocratic, aggressive-sadistic, responsible-hypernormal, competitive-narcissistic and self-effacing-masochistic styles and a decreased accommodating style. Based on these results, promising areas for further research that could improve psychological selection, training and work for Antarctic expedition personnel are outlined.