Professional nursing organizations identify nurse manager (NM) support of staff nurses as an essential component of a productive, healthy work environment. Role behaviors that constitute this support must be identified by staff nurses. In this mixed-method study, supportive role behaviors were identified by 2382 staff nurses who completed the investigator-developed Nurse Manager Support Scale. In addition, semistructured interviews were conducted with 446 staff nurses, managers, and physicians from 101 clinical units in 8 Magnet hospitals in which staff nurses had previously confirmed excellent nurse manager support. Through individual and focus group interviews with NM and chief nurse executives in the 8 participating hospitals, the organizational structures and practices that enabled NM to be supportive to staff were determined. The 9 most supportive role behaviors cited by interviewees were as follows: is approachable and safe, cares, “walks the talk,” motivates development of self-confidence, gives genuine feedback, provides adequate and competent staffing, “watches our back,” promotes group cohesion and teamwork, and resolves conflicts constructively. Supporting structures and programs identified by managers and leaders include the following: “support from the top,” peer group support, educational programs and training sessions, a “lived” culture, secretarial or administrative assistant support, private office space, and computer classes and seminars.