Health care professionals are certain to be among the key personnel in responding to a deliberate use of chemical or biological agents against a human population. It is consequently vitally necessary that those personnel who may be affected by such use gain a basic understanding of their nature and of the principles of how to respond. Similarly, a chemical or biological deliberate event, or “CBDE” for short, would place exceptional strain on the public health sector; thus, public health personnel also need to have a basic understanding of how to manage an effective public health response to CBDE. As the United Nations’ public health agency, WHO has an important role to play in the global public health response to, preparedness and readiness for events involving possible deliberate use of biological and chemical hazards. That is why the Biosecurity and Health Security Protection Unit has developed this online training on basic knowledge in managing the consequences of a Chemical and Biological Deliberate Event for all health professionals worldwide. The course comprises an introduction, four modules and a final evaluation covering an overview of how to manage the consequences of a Chemical and Biological Deliberate Event as an health professional.