Professionals working in the fields of trauma, victim assistance, mental health, law enforcement, fire response, emergency medical services, and other professions are exposed to traumatic events on a regular basis; in some cases, workers are exposed every day. Vicarious trauma (VT) refers to the exposure to the trauma experiences of others, considered an occupational challenge for all of these professions. Research can assist in development of strategies to avoid being left vulnerable to negative impacts of this work, known as vicarious traumatization or secondary traumatic stress (STS). This article reviews existing research and outlines a research agenda for addressing vicarious traumatization/STS in the workplace. The review is organized by the 4 steps of a public health approach: (a) defining the problem including measuring the scope or prevalence, (b) identifying risk and protective factors for negative outcomes, (c) developing interventions and policies, and (d) monitoring and evaluating interventions and policies over time. A research agenda for the field is put forward following these same steps.