CHEC III is organized in 15 Volumes and closely follows the organization used in the previous edition:
Volumes 1 and 2: Cover respectively three- and four-membered heterocycles, together with all fused systems containing a three- or four-membered heterocyclic ring.
Volume 3: Five-membered rings with one heteroatom together with their benzo- and other carbocyclic-fused derivatives.
Volumes 4, 5 and 6: Cover five-membered rings with two heteroatoms, and three or more heteroatoms, respectively, each with their fused carbocyclic compounds.
Volumes 7, 8 and 9: Dedicated to six-membered rings with one, two, and more than two heteroatoms, respectively, again with the corresponding fused carbocylic compounds.
Volumes 10, 11 and 12: Cover systems containing at least two directly fused heterocyclic five- and/or six-membered rings: of these Volume 10 deals with bi-heterocyclic rings without a ring junction heteroatom, and Volume 11 deals with 5:5 and 5:6 fused rings systems with at least one ring junction nitrogen, while Volume 12 is devoted to all other systems of five and/or six-membered fused or spiro heterocyclic rings with ring junction heteroatoms.
Volumes 13 and 14: Seven-membered and larger heterocyclic rings including all their fused derivatives (except those containing three- or four-membered heterocyclic rings which are included in Volume 1 and 2, respectively).
Volume 15: Author, ring and subject indexes.