The main types of cyano-containing electron acceptor molecules, particularly those derived from TCNQ and DCNQI accepters, have been reviewed. Ring substitution, the presence of heteroatoms and extended n-conjugation have been used as the principal structural modifications on the acceptor framework. Recent examples of C-60 based electron accepters bearing an acceptor organic addend and other single-component donor-acceptor systems exhibiting semiconducting behaviour are also discussed.