The Institute of Development Studies (IDS) has contributed to African agricultural policy debate which has featured prominently in growth and poverty reduction assessment in sub-Saharan Africa. This debate has rekindled interest in the use of agricultural input subsidies to promote food security nationally and at household level. After the enforced withdrawal of these agricultural subsidies during the structural adjustment era, their re-introduction as 'market-smart' subsidies has led to several assessment studies. This article draws on evidence from five countries and a detailed study in Ruvuma Region, Tanzania. These subsidy programmes were reported to be successful in increasing maize yields and reducing poverty and had positive spillover effects on input use by non-recipients and private sector development in rural areas. However, unclear programme objectives and serious implementation problems prevented most of these programmes from being effective. These results underline the controversial nature of subsidy policies, with contemporary debate mirroring historical controversy.