Abstract <p>The review discusses the main achievements of ecotoxicokinetics as a section of ecotoxicology in the research of patterns of ecotoxicants distribution, accumulation and transformation in the environment and the influence of these processes on the manifestation of toxic effects in ecosystems. The paper indicates the role of ecotoxicokinetics in the development of methods for removing ecotoxicants from ecosystems using biotransformation and bioaccumulation and improving environmental pollution monitoring. Special attention is paid to the current study of the behavior of pharmaceuticals, microplastics, and nanoparticles in ecosystem components, as well as to analysis of problems encountered and approaches to their solution within the framework of ecotoxicokinetics.</p>