Developments in the size of government in GECD nations over the last two decades have differed markedly from 'the generally steady rise in the relative size of the government sector during the 1950s and 1960s. This paper discusses the nature and limitations of measures of the size of government before proceeding to examine trends in the size of government in GECD nations through the 1970s and 1980s. After examining aggregate trends, the paper turns to looking at how the structure of government has changed. The findings for different nations are compared and contrasted and the patterns and trends related to social, economic and political factors. The analysis reveals that overall differences in government outlays between countries can largely be explained by differences in the level of spending on transfer payments.