Researchers, policy makers and practitioners alike have in recent years acknowledged a growing tendency towards opening up the innovation process by combining internal organizational assets with external actors’ resources. However, opening up the innovation process usually also entails revealing ideas, which may result in misappropriation. The purpose of this thesis is to investigate tensions related to the openness-appropriability relationship; this is done in three studies. The first study concerns a specific contextual factor that is likely to stress the openness-appropriability tensions: the location of external partners in innovation. The second study relates to the way managing openness-appropriability tensions affects performance, and the third study involves a theoretical discussion about the nature of the tensions occurring in the openness-appropriability relationship, i.e. paradoxical, dilemmatic, or dialectical. The first two studies apply quantitative methods, using survey data, while the third is a conceptual paper. The findings from the first study indicate that the use of different groups of appropriability mechanisms varies across various types of openness and that the location of external partners in innovation refines these linkages even more. The second study’s main takeaway is that the higher appropriability intensity, i.e. the extent to which appropriability mechanisms are put into practice, explains higher performance outcomes. The third study suggests that the tensions between openness and appropriability are more likely of paradoxical nature. From a theoretical perspective, findings indicate that paradoxical tensions between openness and appropriability may have a spatial dimension, and that these tensions should also be investigated in regards to performance. Managerial implications point out that opening up to innovation partners located abroad is likely to require more costly appropriability mechanisms.