ABSTRACTThis article presents new evidence on the crime‐reducing impacts of a high‐quality, intensive early childhood program with long‐term follow‐up, evaluated by a randomized controlled trial. Proportionately, more women than men decrease their criminal activity after participating in the program. This gender difference arises because of the worse home environments for girls, with corresponding greater scope for improvement by the program. For both genders, treatment effects are larger for the least‐advantaged children, as measured by their mother's education at baseline. The dollar value of the social cost of criminal activity averted is higher for men because they commit more costly violent crimes.