Strategy-making at the subsidiary level, in particular the phenomenon of subsidiary initiative, has received increasing research attention during the last years. However, it is far from clear how subsidiary initiatives can be theoretically conceptualized, as theory building has mostly remained on a rather abstract organizational level. In this paper, we present subsidiary initiative as a multilevel phenomenon. Based on a comprehensive literature review, we highlight research avenues that may enlighten our understanding of antecedents, execution and outcomes of the initiative process. Further, we propose to integrate different theories from the individual, team, organizational and network level to advance research in this area. Two ways of theory integration are suggested: ?aggregation? theories that guide the emergence of initiatives from the individual up to the network level; and ?bridging? theories, which link the micro-macro divide and may help us to develop a more holistic view of subsidiary initiative and simultaneously test theoretical propositions at multiple methodological levels.