Objectives: We investigated the associations between the Big Five personality traits and occupational burnout in firefighters and the mediating role of achievement goals in this relationship. Methods: Two hundred twenty male firefighters from 20 to 62 years old participated and mediation analyses were performed. Results: The results showed that neuroticism was positively related to the three dimensions of burnout, both directly and through mastery avoidance goals. Mastery approach goals mediated the relationships between conscientiousness and physical fatigue and between openness to experience and physical fatigue. Conclusion: Three of the Big Five personality traits, neuroticism, conscientiousness and openness to experience, and achievement goals, may be important factors in understanding and preventing firefighter burnout.