The primary audience for this guidance is persons working directly in vector-borne disease prevention and control, including programme managers, researchers and field workers. A brief technical background is provided for the benefit of persons without expertise in vector-borne diseases; readers working in the field may wish to skip the background section and begin with the discussion of ethical issues and values in Chapter 3. The guidance cannot offer universally applicable answers to the complex ethical issues raised, nor can it provide a checklist of issues that are necessarily relevant in all situations. Rather, its goal is to help readers recognize aspects of their work that raise significant ethical challenges and to respond to these challenges in accordance with internationally accepted values and norms.