This article examines the role of the European Union (EU) and United States as actors in international disaster relief. We take the analysis of �actorness� one step further than normal by assessing the extent to which different aspects of EU and US actorness led to effectiveness in actual outcomes. In doing so, we make two contributions. First, we provide a rare comparison between EU and US foreign policy actorness, shedding light on the actor capability of each bloc in the area of international disaster relief. Second, we specify the relationship between actorness and effectiveness, a relationship which is too often assumed rather than explored. Using previous research of EU and US actorness as a starting point, we link four aspects of actorness to effectiveness and assess the resulting hypotheses using the case of the 2010 Haiti earthquake. We find support for our proposed links between actorness and effectiveness, although further research is needed before robust conclusions can be drawn.