Objectives The aim of this research is to present the current achievements of advanced techniques used in sample preparation in bioanalytics. This paper will present the classification of these techniques, and the principles of performance as well as a review of their advantages and disadvantages compared to standard techniques such as SPE and LLE. Finally, through a critical review of selected scientific papers, their application in bioanalytics will be assessed. Materials and Methods For the purpose of this paper, relevant scientific and professional literature in bibliographic databases (PubMed, Web of Science, ScienceDirect and Scopus) will be searched using the following keywords: bioanalysis, sample preparation, bioanalytical methods, bioanalytical techniques, microextraction techniques. Books and websites that address this issue will also be reviewed. Results This review describes and clinically considers the application of different types of microextraction techniques to concentrate different compounds in biological samples. These samples have very complex matrices that can interfere in such analyzes. During the development of bioanalytical methods, the key parameters are their sensitivity and extraction efficiency, given the expected low concentrations of analytes in biological samples. In recent years, the use of microextraction in bioanalytics has increased significantly, mostly for determining the therapeutic dose of drugs, as well as pharmacokinetic and metabolomic studies. These techniques enable automation, miniaturization, high efficiency of analytical methods, and also shorten the total analysis time. In addition, they can be combined with many analytical instruments, which further expands their application for the extraction of various compounds. These features have opened up new applications for various in vitro and in vivo studies. Conclusion More research is needed to discover all the advantages and limitations of these techniques, but no doubt their development will continue in the future in terms of even more sensitive and selective extraction phases, which may lead to further miniaturization of these techniques and greater automation of sample preparation.