This review describes a literature survey of 1,3,5-triazepines. The investigated heterocycles were the monocyclic and fused 1,3,5-triazepines. The different sections of the paper cover: theoretical methods, spectroscopy aspects, thermodynamic aspects, synthesis and reactions of the monocyclic and fused heterocycles incorporated into the 1,3,5-triazepine moiety. The biological evaluation of the target compounds are also described as well as their synthetic applications. The reaction mechanisms are discussed.