L-type voltage-gated calcium channels (VGCCs) are multisubunit membrane proteins that regulate calcium influx into excitable cells. Within the last two years there have been four separate reports describing the structure of the skeletal muscle VGCC determined by electron microscopy and single particle analysis methods. There are some discrepancies between the structures, as well as reports for both monomeric and dimeric forms of the channel. This article considers each of the VGCC structures in terms of similarities and differences with an emphasis upon translation of data into a biological context. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.