Some child molesters abuse children of both genders. The purpose of this study was to explore the relationship between gender crossover and victim age. The authors hypothesized that offenders who molested children of both genders would be more likely to have very young victims and that offenders who molested very young children would be more likely to abuse children of both sexes than offenders with older victims. The sample consisted of 362 sex offenders being considered for civil commitment as sexually violent predators in Florida. Data were collected from file reviews. The relationship between victim age and gender crossover was examined using chi-square and multivariate logistic regression analyses. The proportion of offenders with victims of both genders significantly increased as the victims' ages decreased, and sex offenders with preschool-age victims were most likely to have abused both boys and girls. A sex offender with a victim 6 years of age or younger had more than 3 times the odds of having perpetrated sex crimes against both genders than a sex offender with only older victims. Sex offenders with victims of both genders had more than 3 times the odds of having preschool victims. The presence of a major mental illness increased the odds of gender crossover more than threefold. Pedophilia increased the odds of having victims younger than 6 more than 11-fold. Implications for practice are discussed.