Unprofessional behavior, bullying, and microaggressions result in diminished staff psychological safety and can threaten patient safety. This narrative review identified five categories of contributors to unprofessional behavior in acute care, including the inability to speak up and lack of manager awareness or urgency. Women, people with disabilities, and staff from minoritized groups were most at risk of being targets of unprofessional behavior. The authors present a program theory of contexts, mechanisms, and outcomes.