This bachelor thesis is focused on ecological and environmental problems in large protected areas in Slovakia. The first part contains informations about Slovak large protected areas in general, interprets informations about current status in Slovak biosphere reservations, and shortly describes ecosystems in Slovakia. The second part deals with international environmental conventions, provides fundamental informations about nature and landscape protection obligations. The third, more extensive part is devoted to monitoring of habitats and species of European importance in Slovakia where is indicated their current state and impacts that affect them. The fourth part summarize informations about prohibited activities in individual levels of protection. The fifth part explains environmental crime, deals with crimes committed in nature, contains informations on the evolution of environmental crime over the years 2006 – 2018, informs about sanctions that can be obtained for individual types of crime and describes the discovered types of activities related to environmental crime in large protected areas in Slovakia. The sixth part includes informations about environmental political strategy in Slovakia and worldwide. The seventh and the last part contains informations about the state of ecosystems in protected areas worldwide.