Unprotected sexual intercourse is the principal means of transmission for HIV; the virus associated with AIDS. In the absence of effective medical treatment, the modification of sexual behaviour remains the most important method of containment. A cognitive behavioural model of risky sexual behaviour is described. Intervention strategies suggested by the model are discussed in some detail. These include a novel procedure that potentiates state dependent memory effects. Finally, three cases are presented in order to underscore key points.