This chapter contains sections titled: Introduction Free radical rearrangements Other routes to triphenylmethyl radicals The persistent radical effect Properties of triphenylmethyl radicals Steric effects and persistent radicals Substituted triphenylmethyl radicals and dimers Tris(heteroaryl)methyl and related triarylmethyl radicals Delocalized persistent radicals: analogues of triarylmethyl radicals Tetrathiatriarylmethyl (TAM) and related triarylmethyl radicals Perchlorinated triarylmethyl radicals Other triarylmethyl radicals Diradicals and polyradicals related to triphenylmethyl Outlook Acknowledgements References