Catfishes belonging to Ictaluridae, Claridae, Pangasidae and Siluridae are widely distributed in different parts of the world, and their culture has been a traditional practice in some parts of Southeast and South Asia. Like many other warm-water species, catfish are valued as high-quality fish in certain areas, whereas in others they are considered as medium- or low-quality fish. Their hardy nature and ability to remain alive out of water for long periods have been of special value in tropical countries, and there is a specialized trade in ‘live fish’ (a collective name for species that have accessory respiratory organs and can live out of water for long periods) in some areas, as in eastern India. Catfish are also valued for recreational fishing in the southern parts of the USA. Nevertheless, the recent wide-spread interest in commercial catfish farming was largely generated by the development of a multimillion dollar catfish farming industry in the southern USA. Since the 1900s,considerable research and development efforts have been directed towards the formulation of suitable methods of farming and the processing and promotion of catfish products. Channel catfish, the main species used in farming in the USA, have been transplanted to a number of countries in southern Europe, Africa and Central America, but no comparable enterprises have developed in these regions. These introductions have, however, resulted in greater attention being paid to improving techniques of farming local species of catfish in many countries.