This study examined associations between maltreatment and early developmental vulnerabilities in a population sample of 68,459 children (Mage = 5.62 years, SD =.37) drawn from the Australian state of New South Wales, using linked administrative data for the children and their parents (collected 2001–2009). Associations were estimated between (a) any maltreatment, (b) the number of maltreatment types, and (c) the timing of first reported maltreatment and vulnerability and risk status on multiple developmental domains (i.e., physical, social, emotional, cognitive, and communication). Pervasive associations were revealed between maltreatment and all developmental domains; children exposed to two or more maltreatment types, and with first maltreatment reported after 3 years of age, showed greater likelihood of vulnerability on multiple domains, relative to nonmaltreated children.