This chapter defines the terminological differences between the terms 'fire-setting', 'arson' and 'pyromania', including their place in current diagnostic manuals. An epidemiological perspective on fire-setting in those with mental disorder as well as classification systems and theories of fire-setting with prevailing conceptual models of fire-setting and mental disorder is described. Current approaches in the risk assessment of fire-setting and psychological and pharmacological interventions in fire-setting are discussed. Finally, a care pathway to guide clinical and risk assessment of the patient with fire-setting as a feature of their behaviour or history is suggested.