Mosaic is a painting technique in which small, multicolored pieces, ceramics or glass are pressed into a soft base of cement or fresh plaster. Mosaic parts can be regular or irregular cubes and they are used to decorate various elements of architecture in public or private buildings. The art of mosaic originated around 3000 BC in Mesopotamia and Egypt. The original mosaics served as wall reinforcement. Later, the mosaic appeared in Greek and Roman culture and spread throughout the rest of Europe. In the Republic of Croatia, the art of mosaics is visible in the Euphrasian Basilica, which is under the protection of UNESCO. The study is organized in ten chapters. The introduction briefly discusses the mosaic technique and its application. The next chapter shows how to make a mosaic. The third chapter lists the materials and tools used in the work on the technique. A brief historical overview of the art of mosaics is provided in chapter four. The fifth and sixth chapters deal with contemporary and modern mosaic. In the seventh, eighth and ninth chapters, the ways of applying the mosaic technique in working with students in school and extracurricular activities are given. Finally, the concluding part reviews the thesis as a whole.