This paper draws from a research project (the «Milan Privatisation Study») that offers a comprehensive evaluation of the welfare impact of a policy usually regarded as highly successful and vastly imitated worldwide: the privatisation policy pursued in the UK by Mrs Thatcher’s government (1979-1990) and subsequently by Mr Major’s government (1990-1997). The paper considers the impact of privatisations on five types of agents: firms, employees, shareholders, consumers and tax-payers. The main conclusion of our study is that British privatisations had modest effects on the efficiency of production and consumption. On the other hand, privatisations did have important effects on the distribution of incomes and wealth. Thus the outcome of privatisation in the UK was not unambiguosly a Pareto improvement.