While development cooperation largely consists of policy advice, the suggestions and inputs on development that policymakers in the Global South receive from donors and other international actors, little research exists on what makes policy advice useful to these policymakers. The aim of this study was to find out why policymakers in the Global South find some advice useful and some not. This was done through a field study in Kenya, using interviews with 23 policymakers and advisors. The analytical framework that was applied to the material reconciled the SCL model of analysing policy advice in terms of its content, with a critical postcolonial perspective which regarded the delivery of advice. The study showed that  the usefulness of policy advice for Kenyan policymakers is as dependent on the delivery of the advice as it is on its content, unlike what has been implied previously by Western research on think tanks. The study also concluded that not only is it possible to merge the two theoretical perspectives of policy advice and postcolonial theory, despite the difference in abstraction levels, applying a postcolonial perspective can be crucial in order to examine the full scope of what makes policy advice useful to policymakers in the Global South.