The link between childhood maltreatment and subsequent offending behaviour is well established, and data from the child welfare system is commonly used to examine the maltreatment-offending association. This study used data from the first national comparative profile study of high-support needs children undertaken in Australia to determine which factors differentiate offenders from non-offenders among a sample of high support needs young people. It was hypothesised that young people with offending behaviour would differ from those without offending behaviour on various demographic, background, and emotional and behavioural factors. As hypothesised, young people with offending behaviour were more likely to have experienced a range of adverse background factors and displayed more problematic behaviours than young people without offending behaviour; however, logistic regression analyses indicated that four factors are significantly associated with offending: older age, damaging property, substance abuse and conduct problems. Placement in residential care, being placed in care due to reasons other than physical abuse, being of Aboriginal and Torres Strait Islander descent and poor social adjustment were all marginally associated with offending behaviour. This study highlighted some of the potential mechanisms responsible for the increase in offending behaviour among youth in the child welfare system. Understanding these mechanisms is imperative for researchers, practitioners and policy makers alike for the development of effective intervention strategies.