Background: MicroRNA (miRNA) are a class of short non-coding RNA molecules that regulate gene expression at the post-transcription level by binding to mRNA. By affecting many physiological processes, including cellular proliferation, differentiation, and apoptosis, they have a major impact on the development of cancer as well as other diseases. Hence, miRNAs could serve as potential tumor biomarkers in e.g. early diagnostics, predicting responses to therapy, monitoring relapse, and molecular classification of tumors. Aim: miRNA detection requires various sophisticated strategies due to the small size, sequence similarity among family members, and often very low levels of miRNAs in analyzed samples. This review describes standard techniques of miRNA detection, such as the reverse transcriptase polymerase chain reaction, microarrays, and next-generation sequencing, and compares several commercially available detection kits. Major emphasis is given to newly developed technologies and methods, which could make the analysis cheaper and quicker. We present, for instance, alternative amplification techniques (isothermal amplification and the hybridization chain reaction), different types of nanomaterials, special proteins used in miRNA analysis, and a number of biosensors utilizing optical or electrochemical detection. Conclusion: The importance of miRNA has led to a huge increase in the number of new methods. Most of them, however, have not been tested on clinical material, and thus it is difficult to assess their potential usefulness in routine practice. Their commercial application strongly depends on strict validation with standard techniques using not only model systems, but also clinical samples.