Police officers, firefighters, and emergency medical workers are at a relatively high risk of experiencing external workplace violence (EWPV), that is, violence initiated by people outside the organization. Based on criminal opportunities theories, the aim of this research was to study to what extent socio-demographic and work characteristics are related to experiencing EWPV. In addition, the aim was to explore how these relations differ between the three types of emergency responders. Data from a workplace violence survey of the Ministry of the Interior and Kingdom Relations of the Netherlands was used, from which emergency medical workers (n = 264), firefighters (n = 255), and police officers (n = 296) were selected. Results indicated that police officers experienced most and firefighters experienced least EWPV. Younger professionals and professionals who have more frequent and risky contact experienced more EWPV. The expectations that males and those with less skills or experience to avoid EWPV experience more EWPV were not convincingly supported. The relationships between characteristics and EWPV, and the explanatory power of the models, differed between types of emergency responders. The studied characteristics best explained variations in EWPV of police officers, and therefore prevention of EWPV by addressing these characteristics will be most successful for police officers. The prediction of EWPV should be improved, for example, by studying the relationship with “attractiveness” or “vulnerability” of the possible victim, such as psychological characteristics of professionals. The study showed that research about indicators and prevention of EWPV should be aimed at separate professions.