This dissertation examines networking behavior that is instrumental for career success. The first paper (conceptual) proposes that instrumental networks are created from actors' network structure and ties. Egocentric sparse networks enable access to novel information which may help actors recognize the high status of those (alters) with whom they try to forge ties. When high status alters become actors' mentors or sponsors, the latter legitimatize the status of the former, enhancing the probability for actors to develop relations with other influential people in the organization. The second paper (qualitative) explores how individuals engaged in networking. A three phase sequential, iterative, and 360° process emerged from the indepth interviews answering “who, why, when, and how” successful individuals engaged in networking. Based on a survey, the third paper found that there were no gender differences except for one networking behavior and that the probability of having a female mentor who would provide career support was higher for women than for men.