The generation of "cold light", visible to the human eye, by chemical reactions has attracted the attention of the scientific community since the beginning of this century. Besides the academic interest in the elucidation of the mechanisms of excited state formations, many chemiluminescence reactions have found widespread analytical applications. Moreover, the phenomenon of chemiluminescence can also be used as a tool in undergraduate and college teaching. In this article, we describe several known chemiluminescence demonstrations, which are suitable for school teaching. The main objective of this work is to produce didactic material in Portuguese to stimulate Brazilian secondary and high school teachers to use these experiments in the classroom. The demonstrations include singlet oxygen emission, the luminol reaction, oscillating chemiluminescence and the peroxyoxalate reaction.