INTRODUCTION: In recent years, there has been increasing interest in firearms in Poland, which may be related to the armed conflict in the territory of our eastern neighbors. Programs are being implemented to familiarise and promote sport shooting in society. The aim of this research was to obtain information on the knowledge of persons serving in Fire Protection Units (FPU) in safety in incidents with firearms and firearms ammunition, the risk of their use, their use or effects of such use. MATERIAL AND METHODS: 228 people took part in an anonymous survey. The study was addressed to both: professional firefighters in State Fire Service (SFS) and Volunteer Fire Brigade (VFB). The research tool was a proprietary questionnaire composed of 10 questions. The questionnaire was made available to respondents online using Google Forms. RESULTS: Professional firefighters more often indicated the correct answer, i.e. “Strategy for dealing with the casualty on the battlefield” (61% vs 64%, p = 0.020). In the question checking the knowledge of the possibility of sending firearms and ammunition, volunteer firefighters more often indicated the answer that it is absolutely forbidden (79% vs 58%, p = 0.032). In the question regarding the self-assessment of the ability to secure a potentially loaded firearm, it was shown that the assessed skill improved statistically significantly with age (p = 0.030). CONCLUSIONS: Firefighters’ knowledge of safety rules in incidents involving firearms is insufficient. Completion of a course in qualified first aid, professional development covering only Tactical Combat Casualty Care (TCCC) issues, and military service for firefighters are insufficient during activities where there is a risk of contact with firearms and ammunition. Firefighters do not use TCCC safety considerations against an armed casualty when the event is a fire incident. Firefighters presented a low level of knowledge of current legal regulations with regard to the possession, transport, and protection of firearms and ammunition.