Child sexual assault is much more likely to happen in environments where an adult has a lot of power over children and is not likely to be observed, or can rely on other adults not to tell. This means that child sexual assault is most likely to happen within families, or within institutions which have care over children.

Families are the most common place where children are abused (sexually or otherwise). Within families, fathers are most likely to be the person who perpetrates the abuse, although siblings, mothers, step-fathers, grandparents, and more distant relatives may also be offenders. Perpetrators are more likely to be male than female, although in the years we have been operating, SAMSSA has been told of many female perpetrators, including mothers, by survivors.

Child sexual abuse can and does take place within any institution responsible for the care of children. The types of institutions or care situations in which boys are most commonly abused include schools (particularly boarding and religious schools), orphanages, hostels, and disability support services, along with sporting or activity-based institutions such as scouting organisations. In these places, the abuse may be perpetrated by carers, or by other boys.

Boys are also assaulted by strangers, usually in secluded public places.

According to The Australian Bureau of Statistics (2013), 75% of men surveyed knew the person who sexually assaulted them, and 25% were assaulted by strangers.