The impact of multinational companies (MNC) on Irish industrial relations practice has long been the focus of scholarship and debate. The orienting question has generally been which effect has had the greater influence: the so-called "country-of-operation" or "country-of-origin" effect? The general view among Irish industrial relations scholars has been that the former effect has exerted a greater influence. It is argued that the host-country effect, once thought of as the predominate effect or pattern, has increasingly been overridden by "country-of-origin" effects. Issues of union recognition, industrial relations practices and outcomes, collective bargaining and incomes policies, industrial conflict, and human resource policies are examined.