The authors present chemiluminescence in glowsticks from the theoretical and practical point of view. Chemiluminiscence is a process in which light of characteristic wavelengths is emitted as a result of an exothermic chemical reaction. Glowsticks can therefore be used as an interesting and simple teaching tool in chemistry and physics classes in the elementary and secondary schools. In the first part the authors introduce the concepts needed to understand luminescence as well as the mechanism of chemiluminescence in glowsticks. Analysing the elementary and secondary school curricula of natural science, chemistry and physics the authors identify various topics in which the experiments with glowstics could be used. They present several optimised and innovative experiments suitable for the elementary and secondary school.