This study uses data from the Canadian Incidence Study of Reported Child Abuse and Neglect, 1998 (CIS-1998) to compare cases of male and female-perpetrated child sexual abuse. There were a total of 345 sexual abuse investigations for which information about the sex of the perpetrator was available: 89% of perpetrators were male and 11% were female. Investigations involving female perpetrators were more likely to involve two or more children victimized by the same perpetrator, to have a co-perpetrator identified by the investigating worker, and to involve younger victims. Investigations involving male perpetrators, compared to those involving female perpetrators, were more likely to have been referred to child welfare by a professional. The author concludes that more research into female-perpetrated child sexual abuse is necessary to better understand these differences. Results should be interpreted cautiously, as analyses were based on only 37 investigations involving female perpetrators.