The victim-choice polymorphia of 178 sexual aggressors divided into six subtypes, incest offenders, pseudoincest offenders, sexual aggressors of familiar children, sexual aggressors of unfamiliar children, sexual aggressors of familiar women, and sexual aggressors of unfamiliar women, was compared. Results showed that sex offenders remained stable in their choice of victim from one offence to another in terms of victim age, victim gender, and aggressor-victim relationship. Subjects characterised by high levels of polymorphia were pseudoincest offenders and sexual aggressors of familiar women, whereas sexual aggressors of both unfamiliar women and unfamiliar children were characterised by low levels of polymorphia. Recommendations regarding how to further refine sex offender typologies are discussed.