During preclinical research and development from individual studies on laboratory animals, different data are collected on certain species or strains of laboratory animals, especially control groups, in order to determine the differentiation of individual parameters in relation to test groups and literature available. The result of the development of toxicology, as well as all its branches (clinical pathology, pathohistology, toxokinetics, etc.) gives grounded importance to toxicological studies, which also contributes to preclinical development. In order to understand how the newly tested substance will affect the human body and health, before conducting clinical trials in humans, it is necessary to conduct preclinical research on animals, primarily rodents, and at a later stage of research and development on other animal species. Harmfulness of test substances to laboratory animals in toxicological studies is monitored through a number of parameters, and among them are the monitoring of changes in the parameters of hematology, biochemistry and organ weight. The aim of the study was to collect data from several toxicological studies, more precisely the results of their control groups on eight-weekold male and female Sprague Dawley rats and eight-week-old male CD-1 (Charles River) mice, so that they could be used later for easier understanding and interpretation of the obtained results (parameters), from the same or similar toxicological studies. I compared the obtained results with the available literature data. According to the protocol, and after the completion of toxicological studies, the animals were weighed, blood was sampled for hematological and biochemical analyzes, and certain organs were sampled after the autopsy. These parameters are relevant to this paper. After blood analysis on an automatic hematology analyzer Sysmex XT-2000iV and a clinical chemistry analyzer Olympus AU480, hematological and biochemical parameters were obtained. The obtained data are in accordance with the published literature data, which supports the justification of my thesis. They are also important for any institution that deals with toxicological studies, in order to facilitate the interpretation of the results of future studies. The aim is to supplement the previously obtained results with the data of new studies (control groups) to greatly increase their significance and credibility.