The role of uncertainty in the global economy is now widely recognized by policy-makers but its effects on the international fi…nancial system are less understood. In this paper we assess the impact of uncertainty on the interconnectedness within the international system of equity prices. In this respect, we extend the measure of connectedness put forward by Diebold and Yilmaz (2009) by allowing for non-linear effects through the estimation of a non-linear Threshold VAR model whose regimes depend on the level on uncertainty. Results clearly show that high uncertainty tends to generate more connectedness among equity indexes of a set of advanced and emerging countries. From an economic policy point of view, this result suggests that in the presence of high uncertainty, an adverse …financial shock in a speci…fic country is likely to propagate more widely and more strongly to the whole fi…nancial system. This result advocates for a close real-time monitoring of uncertainty measures.