The publication aims to analyze public security and public order in conceptual and institutional terms as an analytical category of security sciences. The legislator defines neither public security nor public order. So far, they have been treated mainly as categories of administrative law. It is therefore important to assign them analytical content in the new scientific discipline. The research results allowed for the presentation of the thesis that public security and public order are mainly connected with protection against pathological phenomena occurring in the public space, which are minimized by institutions established to ensure it. These categories should constitute the research field (subject) of the security sciences. The research problem formulated in the form of the question: How are public security and public order treated in definitional and institutional terms? The problem was solved based on a critical analysis of the literature. The paper uses theoretical research methods, including analysis of literature and phenomena occurring in society and inference – as a cognitive factor of the subject of analysis. A critical analysis of the literature on this issue played a large role in the cognitive process.