This chapter reviews empirical literature on foreign aid and QoG. The chapter begins with a description of how scholarship on foreign aid and QoG developed in conjunction with prominent debates in the development community. The chapter discusses three major debates: whether or not QoG moderates foreign aid effectiveness, whether or not donors give aid selectively based on QoG, and whether or not foreign aid undermines or can help build QoG. With regard to aid effectiveness, the most recent literature suggests that aid can be effective even under conditions of poor QoG. With regard to selectivity, the existing literature shows an increasing selectivity for overall aid flows since the end of the Cold War and provides evidence of selectivity in terms of type of aid. The evidence that aid undermines QoG is not as strong as has been claimed by some of the initial studies in this literature. The chapter concludes by suggesting ways forward for all three literatures.