Exposure to child maltreatment is associated with physical, emotional, and social impairment, yet in Canada there is a paucity of community-based information about the extent of this problem and its determinants. We examined the prevalence of child physical and sexual abuse and the associations of child abuse with early contextual, family, and individual factors using a community-based sample in Ontario. The Ontario Child Health Study is a province-wide health survey of children aged 4 through 16 years. Conducted in 1983, a second wave was undertaken in 1987 and a third in 2000-2001. The third wave (N=1,928) included questions about exposure to physical and sexual abuse in childhood. Males reported significantly more child physical abuse (33.7%), but not severe physical abuse (21.5%), than females (28.2% and 18.3%, respectively). Females reported significantly more child sexual abuse (22.1%) than males (8.3%). Growing up in an urban area, young maternal age at the time of the first child's birth, and living in poverty, predicted child physical abuse (and the severe category), and sexual abuse. Childhood psychiatric disorder was associated with child physical abuse (and the severe category), while parental adversity was associated with child sexual abuse and severe physical abuse. Siblings of those who experienced either physical abuse or sexual abuse in childhood were at increased risk for the same abuse exposure; the risk was highest for physical abuse. These findings highlight important similarities and differences in risk factors for physical and sexual abuse in childhood. Such information is useful in considering approaches to prevention and early detection of child maltreatment. Clinicians who identify physical abuse or sexual abuse in children should be alert to the need to assess whether siblings have experienced similar exposures. This has important implications for assessment of other children in the home at the time of identification with the overall goal of reducing further occurrence of abuse. Copyright © 2012 Elsevier Ltd. All rights reserved.