Background WISQARS is an interactive, web-based data query system (WBDQS) that is accessible from the internet. It includes modules for fatal and non-fatal injuries, a separate module on violent deaths, and injury costs and maps. Data come from a variety of trusted sources, including national health surveys and health data repositories. CDC created WISQARS in 1999 to meet the data needs of injury practitioners in the United States. Since that time, the audience has expanded to include researchers, policy makers, media, and the general public. Objective The purpose of this evaluation was to assess the focus, quality, usefulness, impact, and outcomes of WISQARS; and to identify gaps and areas for improvement. Data were collected through peer-reviewed and grey literature searches, google searches, an environmental scan of internal and external WBDQS, and a series of stakeholder interviews. Results WISQARS is used as a data source by NGOs, academic institutions, other U.S. federal agencies, and social media websites. Stakeholders most frequently used the fatal and non-fatal modules. The most frequently accessed data were on suicides, poisonings, homicides, motor vehicle crashes, and falls. WISQARS is most often used to respond to data requests, educate decision makers, conduct basic analyses, and teach and plan. Areas for improvement included building more capacity for data visualisations and for users to export both data and graphics, allowing for full mobile responsiveness when accessing, expanding by incrementally including additional data, and developing better support information and guidance on use. Conclusions While WISQARS has been largely a success in expanding access to U.S. injury and violence surveillance data, there are several opportunities to enhance the functionality of the system for the end user. CDC is planning to use innovations in data science to enhance WISQARS’s capacity.