The dominant motivation for taxation in developing countries is to finance public administration and the public provision of economic and social services. Secondary motivations are the redistribution of income and the correction of market imperfections. Although some level of taxation is necessary to achieve these goals, taxation always has costs -- both direct costs to administration and indirect costs associated with the misallocation of resources and with consequences for the distribution of income. The appropriate level of taxation depends on a country's desired role for the state, the efficiency and equity of its public spending, and the efficiency and equity of its tax structure and administration. Although the desirable level of taxation can vary greatly by country, experience over the past decade has shown clearly that: 1) tax reform as a component of broader fiscal reform is at the heart of the stabilization and adjustment process in many developing countries, as noted in Adjustment Lending Policies for Sustainable Growth (World Bank 1990a); 2) Most tax systems in developing countries have high and avoidable costs; 3) tax reform can work and is inextricably linked with other aspects of development policy. Taking these broad observations as a starting point, this paper assesses the lessons from experience in reforming general taxes administered at the national level. It is intended as a brief on issues and options in tax policy and as a review for World Bank economists evaluating tax reform in operational work. The paper provides a concise synthesis of current thinking and practice regarding tax reform in developing countries; reviews the Bank's growing provision of advice on tax reform and its growing use of loan conditions related to tax reform; and makes recommendations regarding the Bank's future country economic and sectoral work, operational lending (adjustment and nonadjustment), and research on tax policy.