In an eight-year review (1991 to 1998) of all consecutive coroners' files in Quebec, Canada, the authors identified a total of 34 cases of victims who were killed by their mothers. Most victims were less than six years of age, and there were several cases in which multiple siblings were murdered. There were 27 mothers in the sample, and 15 of those women committed suicide after the filicide. A psychiatric motive was determined for more than 85 percent of the mothers, and most of the mothers had received previous treatment for a depressive or psychotic disorder. Based on the characteristics of this sample, the authors developed a filicide classification system that is flexible and simple to use but must be standardized to become a useful tool for clinicians.