Background: The purpose of this research was to examine the relationships between selected personality dimensions and occupational burnout among professional and volunteer firefighters. Difficult conditions are the cause of loss of not only health but also life. Such working conditions may cause occupational burnout consisting of employee’s exhaustion. Material and Methods: The group under examination consisted of 164 firefighters, including 76 volunteers aged 19–61 years (M = 32.49, SD = 9.21) and 88 professional firefighters aged 20–49 years (M = 33.85, SD = 10.05). This research employed the Maslach Burnout Inventory and Gough and Heilburn’s Adjective Check List along with the Personality and Axiological Model (MOA) (competences, relations, autonomy). Results: The results of the conducted research indicate differences between the examined groups of firefighters in personality dimensions (Ord: t = –2.739, p = 0.006; Mls: t = –2.159, p = 0.032; competences t = –2.390, p = 0.017). The research also enabled assessing the correlations with occupational burnout. The greatest relationship with occupational burnout in the group of volunteer firefighters concerns succorance (Suc) and total occupational burnout, and the greatest relationship with occupational burnout in the group of professional firefighters pertains to the competence dimension from the MOA model. Conclusions: The results of the conducted research should be related to the cognitive aspect (the application of the new MOA model in this professional group) and attention should be paid to the personality differences between the groups of volunteer and professional firefighters. The application value for more effective work of psychologists with this professional group is also important in terms of the results obtained. Med Pr. 2021;72(5):509–19