The study traces the historical developments in Irish Prison Administration with particular emphasis on the ways in which emerging philosophical and religious ideas related to punishment and reform coalesced with developments in the 'art' of discipline to form the basis for the present administrative structure. The present organisational arrangements are analysed from two main stand-points; - the administrative view related to inputs, social technology and output requirements, particularly within the context of changing societal pressures - the organisational 'reality' as perceived by staff at different levels; a reality developed within the framework of the administrative view but which deviates substantially from that view. While the administrative structure is seen to adapt to take account of changing circumstances related to input, social technology and output, the prison staff who carry out organisational arrangements have developed attitudes, values and behaviour patterns which sometimes deviate from the administrative view. The attitude and behaviour patterns of different levels of staff related to inputs, social technology and outputs are traced by means of in-depth interviews and questionnaires. The relationship between the Department of Justice, which itself has to respond to societal pressures from its Minister, and the prison service is outlined. Pressures on different levels within the prison service are also described. These include: (a) Pressures generated on prison management by external groups, including policy-makers as well as by staff and prisoner groupings, particularly by political or subversive prisoners; (b) Pressures on prison officers from management and from the nature of the task, involving the establishment of legitimacy through the application of a disciplinary regime on reluctant prisoners while being themselves subject to a disciplinary regime developed in the 19th century; (c) Difficulties generated as a result of the often contradictory expectations of professional staff groups and the uniformed service. The social technology employed in prisons, involving hierarchical surveillance of all activities, is described. Differences between types of prison in attitudes and behaviour patterns are also outlined.