A well-functioning government office acts as a co-ordinator of the decision-making system and as such is crucial for the government’s capacity to define and pursue its collective objectives. The “Government Office” is a generic term that refers to the institution(s) at the centre of government responsible for supporting the Prime Minister and serving the Council of Ministers as a collective decision-making body. This paper describes and analyses the functions and organisation of government offices in a comparative context, covering OECD member countries, central and eastern European countries (CEECs), and countries of the Western Balkans (ex-Yugoslavia and Albania). The analysis is based on information gathered by Sigma and GOV (PUMA)1 since the mid 1990’s, supplemented by results of a written questionnaire administered by Sigma and GOV in 2003.