Despite a longstanding debate, at both a theoretical and empirical level, research on the relationship between foreign direct investment (FDI) and intellectual property rights (IPRs) remains scant and ambiguous. As a result, the link between IPR strength and multinational enterprises' (MNEs) propensity to invest is unproven and seemingly dependent on a number of factors. We critically review the theory and evidence of the influence of IPRs on FDI and MNEs' investment location (country) decisions both to 'take stock' of existing knowledge of this relationship and, by identifying gaps in, and shortcomings of prior work, develop a fruitful research agenda. We find that existing empirical work on the IPR-FDI nexus, though skewed in favour of a positive relationship between IPR protection and FDI, is fragmented, inconclusive and unable to square the conflicting theoretical predictions on how the strength of IPRs can affect MNEs' FDI location decisions. Several issues and challenges are highlighted to explain the difficulties of the collective body of past empirical work to provide a definite answer to the question of the impact of IPRs on FDI, from which valuable recommendations are proposed to guide future applied research.