The decision to substantiate is a key factor in determining eligibility for services and decisions to press criminal charges or to remove a child, and it is frequently the basis for selecting samples of maltreated children or to measure recidivism or intervention effectiveness. Although there is a growing body of research on case substantiation in the United States, few studies have examined this decision in other jurisdictions. Using data from the 2003 Canadian Incidence Study of Reported Child Abuse and Neglect, this study examines the profiles of a national sample of 10,010 investigations. Multivariate analyses reveal that substantiation decisions are generally made in a fashion that is relatively consistent with the clinical characteristics of cases. Along with severity of harm, parent risk factors, and housing risk factors, police referrals are among the most important predictors of case substantiation. Cases involving multiple forms of maltreatment are also more likely to be substantiated.