Earthquakes are extremely stressful and difficult moments in life that people unfortunately encounter and one of the worst natural disasters. They are interesting for research by engineers and everyone involved in the protection of buildings and people from natural disasters. The structure of the Earth consists of three main parts - core, mantle and crust. The lithosphere is formed by the Earth's crust and the upper part of the mantle. Geophysicist Andrija Mohorovićić was the first to notice the sudden transition between the crust and the mantle. In his honor, this transition was named Mohorovičić's discontinuity. Continents make up the Earth and are constantly in motion. The branch of geophysics that studies earthquakes and their occurrence is seismology. The main cause of earthquakes lies in the tectonic plates, which are in constant motion due to the heat in the Earth's interior. In the interior of the Earth, their movements are intense at the edges of large tectonic plates. Also, earthquakes can occur within the slabs themselves. There are three ways of movement of tectonic plates. Earthquakes most often occur in places along strong faults, but also at the intersections of faults with different orientations. The larger the faults, the greater the possibility of a stronger earthquake. Shallow earthquakes are earthquakes whose hypocenter is above the Mohorovicič discontinuity. Precisely in the territory of Croatia, all earthquakes are considered shallow earthquakes. The territory of Croatia includes several zones of greater seismic activity. The first major earthquake recorded in Croatia was in 361. Some of the strongest earthquakes in Croatia occurred in Dubrovnik, Ston, Makarska, Zagreb, Sinjsko polje, Vinodol and in the Banovina area. Unfortunately, as a result of some earthquakes, human lives were lost, and material damage was enormous. Although we cannot predict them, strong earthquakes can be expected in Croatia in the future. It is extremely important to remain calm in these catastrophic situations and provide first aid to the victims. In order to provide first aid in the best possible way, it is necessary to collect basic health data about the injured person.