Objectives: The purpose of this study is to assess the relationship between burnout and fatigue and the employment of nurses in several workplaces. Material and methods: The study group consisted of 234 professionally active female and male nurses employed in medical facilities in various regions of Poland. The study was conducted using an online survey consisting of 2 parts: the Maslach Burnout Inventory (MBI) questionnaire and an original questionnaire including questions about demographic, professional and fatigue data. Results: More than half of the nurses (54.70%) worked in an additional place of work. Among those who took on additional work, as many as 87.50% (112 people) reported feeling tired in the last 6 months and 50% (64 people) in this group noticed a negative impact of additional work on their mental health. The analysis also showed a statistically significant relationship (p = 0.038) between employment in an additional place and the occurrence of headache in employees. Conclusions: Financial factors are the main reason for nurses taking up additional employment. Analysis of the results showed that working in >1 place significantly increases the level of fatigue compared to employment in 1 facility. Nurses employed in >1 full-time position were characterized by a higher level of burnout and increased emotional exhaustion. Int J Occup Med Environ Health. 2025;38(4)