While the national testing of Australian school students is now well-entrenched, the educational outcomes of students with additional needs in this country are unknown. Students with a disability may be exempted from national testing and, in the absence of consistent standards for test accommodations and alternative tests, Australian educational authorities continue to be unaccountable for these students. Using secondary data from the Longitudinal Study of Australian Children, it is estimated that 12.3% of study children had additional educational needs (predominantly learning disabilities, emotional and behavioural disabilities and autism) that required specialist services. More than a third of students with additional needs did not participate in national testing. Those students with additional needs who did participate performed at a significantly lower level in comparison to students without additional needs. Further, students with additional needs in public schools were much more likely to have poorer academic outcomes than their counterparts in the Catholic and Independent education sectors.