Key words Strategy implementation Managing large traditional organizations Entrepreneurial behavior 2 ABSTRACT Innovative use of resources to pursue opportunities has become vital for all—even large traditional—organizations. While traditional management literature has identified contextual features to foster entrepreneurial behavior, little research has looked at why—in the same organizational context–some manager's act entrepreneurially and others don't. Integrating different literatures, I suggest that variance in entrepreneurial behavior within the same objective context can be best explained at the individual level. I propose and empirically test a micro-model on how to induce entrepreneurial behavior in large traditional organizations. Using structural equation modeling, I analyze survey data on 150 managers of a large European financial service company striving to become " entrepreneurial ". Results reveal that managers' subjective interpretation of their sociopolitical support and access to resources stimulates entrepreneurial behavior. Contrary to the predictions of the literature, individual cognitive and emotional competencies do not affect entrepreneurial behavior directly, but are critical in shaping managers' perceptions of their " playground for action ". Findings also show that managers' entrepreneurial self-efficacy beliefs—managers' perceived capability to perform entrepreneurial tasks—are a powerful predictor of entrepreneurial behavior. They are critical to translate perceptions of context and individual dispositions into behavior, and represent an important cognitive and motivational device to steer and regulate entrepreneurial behavior.