Chalcogenocarboxylic acid derivatives are a large class of compounds including more than one chalcogenocarboxyl group in which one or two oxygen atoms of the carboxyl group are replaced with sulfur, selenium or tellurium atoms. The chemistry of metal chalcogenocarboxylates has not been explored extensively as that of carboxylates and dithiocarbamates. This volume presents a comprehensive overview of the syntheses and their limitations, structures and reactions of chalcogenocarboxylic acid derivatives, by emphasizing the developments in organic and inorganic chalcogen chemistry over the last 5 to 20 years.