The aim of this thesis is to compare the activities of two companies that perform the same activities from the perspective of environmental management systems. One of these companies does not have an environmental management system and the other is going to implement it by implementing ISO 14001 standard. The work consists of theoretical and application part. In the theoretical part, specialized literature and legal regulations related to the thematic area of work were analyzed. Selected aspects of both companies were characterized and analyzed in the application part. Finally, measures have been proposed to improve their functioning and environmental performance.