This chapter examines historical and current developments in situational approaches to sexual offending. We consider the implications of situational theories for clinical and risk management responses to known sexual offenders, and more widely for the prevention of sexual offending. We conclude that situational factors are a theoretically and practically crucial, but widely neglected, aspect of sexual offending. In our view, neither dispositional nor situational factors alone are sufficient to explain sexual offending. Rather, sexual offences always occur as a result of proximal interactions between individual and situational factors.