AbstractThe current state of scientific and practical results of the application of polycapillary (multichannel) systems to various areas of analytical chemistry is considered. Polycapillary systems consist of a matrix of single capillaries, which can have different geometries and sizes (from 10 nm to n × 102 µm). They are made of various materials based on silica, silicate glasses, and organic polymers. The main types of polycapillary systems, their production methods, and achievements and prospects of their use in various areas of analytical chemistry are considered. Special attention is paid to the use of microstructured optical fibers in chemo- and biosensors.