This article examines a criminal and professional approach to the regulation of preimplantation diagnosis (PGD) in the two Australian States of Victoria and New South Wales. Under the Assisted Reproductive Treatment Act 2008 (Vic), Victorian medical practitioners face criminal sanctions if they ignore legal requirements. The criminal sanctions do not apply directly to patients, but those seeking PGD treatment have to satisfy guiding legislative principles, statutory rules and the controversial new "presumption against treatment" hurdle. On the other hand, the Assisted Reproductive Technology Act 2008 (NSW) does not specifically address PGD and medical practitioners in New South Wales are not subject to criminal sanctions but must follow the National Health and Medical Research Council Guidelines. As far as patients in New South Wales are concerned, PGD is essentially a medical procedure. In both Victoria and New South Wales, PGD practice is relatively liberal compared to that in many other countries, although the Victorian approach is clearly the more restrictive model of regulation with the threat of criminal sanctions overriding the medical practitioner's ethical duty to act in the best interests of a patient.