Progress in Heterocyclic Chemistry, Volume 6, reviews critically the heterocyclic literature essentially published in 1993. The first two chapters are given over to reviews. The first review deals with the subject of the "halogen dance." The second review describes the application of selected "heterocycles as vehicles for synthesis." This type of review dealing mainly with five-membered ring transformations will prove useful to many readers. The remaining chapters describe advances in the heterocyclic field arranged according to ring-size, i.e., three-, four-, five-, six-, seven-, eight-membered rings, and larger rings. Numerous diagrams and a brief index will assist in locating areas of interest.