This final paper presents the fire protection systems inside the Sisak Oil Refinery, which serve to protect tanks for the storage of flammable liquids. Modern society is characterized by accelerated economic development, in which oil plays a special role as one of the most important natural reserves of chemical-organic products. Oil and oil derivatives enable people to have a more comfortable everyday life, betterment and progress of society, but the processing and storage of oil and oil derivatives require strictly controlled conditions, and extraordinary situations such as fires and explosions in plants of this type are possible with far-reaching consequences. It is necessary that in every company that deals with the transportation, processing, storage and distribution of oil and oil derivatives, there is a legal regulation on fire protection, which must be at a high level, and that all conditions and procedures are provided in a timely manner in order to reduce emergency situations to the minimum possible. measure. The fire protection of every company operating in the territory of the Republic of Croatia is defined by the Fire Protection Act [9], by-laws and autonomous sources of law that legal entities are obliged to adopt based on laws and regulations. For this purpose, the Sisak Oil Refinery uses the Risk Assessment and the Fire Protection Plan as a basic document. By inspecting the Fire and Technological Explosion Risk Assessment, the risks for the occurrence of fire and/or technological explosion were identified, and all necessary equipment for fire protection at the object in question was shown. A review of the project documentation determined whether all the necessary systems, devices and equipment for fire protection were designed. In the conclusion of the final work, the compliance of the protection system within the Sisak Oil Refinery with fire safety regulations and the Fire and Technological Explosion Risk Assessment and the Fire and Technological Explosion Protection Plan was assessed.