Notwithstanding their remarkable recent growth, surprisingly little research has hitherto been conducted on the evolving geography of professional and business services in Britain. This paper analyses the results of a detailed survey of 300 small and medium-sized management and engineering consultancies, in investigating the forces underpinning both the striking clustering of such firms in central London and their growth in decentralized locations of East Anglia and South West England. Particular attention is paid to the notion of clustering, the role of demand-side influences, localized ‘collective learning’ processes, and increasing globalization in clustering, and to so-called ‘enterprising behaviour theory’ in explaining decentralization. [ABSTRACT FROM AUTHOR]