The Irish Stock Exchange separated from the International Stock Exchange of the United Kingdom and the Republic of Ireland Ltd in 1995, when the Central Bank of Ireland became the ‘Competent Authority’ for regulation of the Exchange and its member firms. This paper investigates the implications of separation. The regulatory structure prior to separation is examined within the context of the Irish market. The new regulatory regime and its likely impact on investors and quoted companies is assessed through the medium of interview-based research. It is concluded that, owing to continuing association between the two exchanges, separation will have minimal impact on the then listed Irish companies. Whether large Irish companies of the future seek their primary listing in London as they strive to become world players is very likely to depend on the loyalty of the Irish domestic institutions to such companies.