This article presents descriptive findings from the Ontario Incidence Study of Reported Child Abuse and Neglect (OIS). OIS is the first Canadian study to examine the incidence and characteristics of reported maltreatment. The study is based on a survey form completed by child protection workers on a representative sample of 2,447 investigated children. OIS found an incidence rate of reported maltreatment of 21 per thousand children, and a 27% substantiation rate. These rates are compared to those in the United States.