Even though much of the prior sex offender literature focuses on males, recent research has included females as offenders. Such research, however, has been limited by small sample sizes. Several researchers have proposed typologies of female sex offenders that include both females who act alone (i.e., solo offenders) and females who act with another person (i.e., co-offenders), often a male. The current research includes a cross-national sample of 123 females who were solo offenders and 104 who were co-offenders. It was found that the two groups of females were not significantly different in regard to their age, race, time of offense, and the location of the offense. Co-offenders were more likely than solo offenders to have more than one victim, to have both male and female victims, to be related to the victim, and to have a nonsexual offense in addition to the sexual offense listed.