The research is an in-depth, empirical study of the political behaviour of the Church of Scotland; it is primarily intended as a contribution to the territorial field of Scottish politics. The most important aim of the thesis is to assess the overall effectiveness of the Church of Scotland when it takes part in political activities. More generally, the research has three key themes: first, it examines the place of religion in politics by analysing churches as political pressure groups rather than simply looking at voting behaviour; second, it looks at the development of the new Scottish political system, post-devolution; third, it explicitly compares the political behaviour of the Church of Scotland with the Scottish Catholic Church. Chapter two focuses on the political behaviour of the Church and Nation Committee of the Church of Scotland and concludes that its effectiveness is limited, primarily due to a shift in societal values. Chapter three focuses on the political behaviour of the Board of Social Responsibility of the Church of Scotland and concludes that is possesses more potential for influence than the Committee, due to the nature of the issues it is concerned with. Chapter four compares and contrasts the political behaviour of the Church of Scotland with the Scottish Catholic Church, and concludes that the latter is often more effective than the former when they act as political pressure groups. Chapter five analyses the results of the elite survey questionnaires and interviews; one of its main conclusions is that while most Scottish politicians believe the Church of Scotland to be influential, they do not perceive themselves to be personally influenced. The thesis argues that the political influence of the Church of Scotland is varied, depending on which area of policy is being addressed, and the place of religion generally in Scottish politics is becoming increasingly peripheral.