Carbon monosulfide can be generated by photolysis, thermolysis, or discharges of CS2. We have found a high voltage AC discharge works well for production of synthetic quantities of CS. This method yields a mixture of mainly CS and CS2with small amounts of S8and C3S2A stream of CS gas about 85% pure can be obtained if this mixture is passed through a -112°C trap. The ground state of CS is X1Σ+, and its spectroscopy is somewhat unique due to the similar energy levels of the first excited electronic configuration interspersed with the vibronic levels of the second excited state. The reactivity of CS is quite interesting. It will react with Lewis acids and Bronstead acids as well as Lewis bases. It is particularly reactive with halogens, basic amines and thiols, hydrogen halides, electron rich acetylenes, sulfenyl chlorides, and diazo compounds. This range of reactivity will be discussed with the aim of understanding reaction mechanisms and modes of attack. Another very favorable reaction is self polymerization of CS, which can occur explosively. A third body is necessary (wall reaction), and CS polymerization can be catalyzed by certain metals and organometallic compounds. The polymerization process and the structures of the polymer will be reviewed and discussed.