The probability that a young person will have exposure to pornography prior to the age of 18 - the legal age in Australia at which it is permissible to view and purchase such materials - is very high. Parents and policy makers are concerned that this is changing the nature of sexual attitudes, behaviours and intimate relationships and potentially contributing to sexual violence in society. The extent to which it is, is difficult to determine, owing to the scarcity of adolescent-based research and differing conceptions of harm. This paper examines the many factors that underpin pornography exposure, and stresses how the risk factors for exposure and problematic sexual behaviours intersect to contribute to harm.