Passion research is rapidly expanding within the field of entrepreneurship. However, measurement of the passion construct has rarely considered entrepreneurial-thinking employees within established firms, or intrapreneurs. Drawing from identity theory, this dissertation considers a model of employees’ harmonious and obsessive passion for "being entrepreneurial" as antecedents to individual-level intrapreneurial behaviors. Given the important role that managers play in supporting innovative efforts of employees, I examine manager relationship quality as a moderator in the research model. Individual-level resilience of the employee is also considered as a moderator in the passion-to-behaviors pathway. A unique sample of intrapreneurial employees (N=165) provides insights into these relationships. Findings indicate that harmonious passions are positively linked to engagement in intrapreneurial behaviors, while obsessive passions are not. The study found partial evidence of interaction effects between manager relationship and obsessive passion but did not find support for other moderating relationships.