Previous research indicates the ubiquity of microplastics in the environment as well as in the tissues of different groups of organisms. The aim of this thesis is to examine the presence of microplastics in the tissues of tadpoles of the genus Pelophylax inhabiting lakes where the presence of microplastics in water and sediment has been confirmed. The research was conducted on a total of 13 tadpole individuals. Individuals were kept in an aquarium and fed until euthanasia which allowed testing for the presence of plastic particles in the water they were staying in. During their stay in the aquarium, three individuals developed into adult frogs. Tadpoles in the higher stage of development were subjected to a section to isolate organs, and those in the lower stage were analyzed whole. The remains of the bodies of the dissected tadpoles were also analyzed. The presence of microplastics particles was examined in the organs of the digestive system (liver, stomach and intestines), in the brain in individuals who completed the transformation and in the remains of the body. quarium water was additionally analyzed. The organic matter was decomposed using Fenton's reagent Microplastic particles were found in all examined digestive system organs, the brain, body remains, and aquarium water, indicating that amphibians are exposed to plastic particles even in the early stages of life.