The first nationwide prevalence study of child maltreatment in The Netherlands (NPM-2005) was designed as a replication of the National Incidence Studies (NISs) conducted in the United States. Child maltreatment cases were reported by 1,121 professionals from various occupational branches, trained in a detailed registration system of six types of abuse and neglect. In addition, cases registered by the Dutch Child Protection Services (CPS) were analyzed. For 2005, the overall prevalence rate was estimated to be 107,200 (95% CI 102,054-112,882) maltreated children aged 0-18 years, or 30 cases per 1,000 children. Neglect was the most prevalent type (56% of all cases) and sexual abuse had the lowest rate (4%). Of the maltreated children, 47% experienced more than one type of maltreatment. Major risk factors were very low parental education and unemployment. It is worrisome that CPS agencies only see the tip of the iceberg as only 12.6% of all maltreatment cases were reported to the CPS. Training of professionals in observing and reporting child maltreatment is badly needed. The absence of a legal obligation to report in The Netherlands needs reconsideration.