The demographic, symptomatic, psychosocial and diagnostic profile of 104 child firesetters was investigated in a controlled case note and item sheet study of all children referred to an Inner London clinic between 1973 and 1981. Firesetters form a subgroup of severe conduct disorders, and are distinguished by a younger peak age of 8, higher boy/girl ratio and more marked psychosocial disturbance. The paper focuses on the relationships between background factors and firesetting, and also examines the relevance of enuresis and situational antecedents as specific determinants.