The publication of Australian fetal alcohol spectrum disorder (FASD) diagnostic guidelines marks an important step forward in Australia's efforts to prevent FASD. But do we need yet another set of FASD guidelines? At the 5th International FASD Conference, the ever growing number of FASD diagnostic guidelines was identified as a core area of concern by leaders in FASD worldwide. All agreed we need to strive to adopt a single set of guidelines. It is essential that FASD diagnosis advance to incorporate new knowledge and technology. But to date, the field of FASD has seen multiple sets of guidelines published that do not address the important question-How is the performance of these new guidelines superior to the performance of existing guidelines to warrant/justify their introduction into the medical literature?The Australian guidelines include FAS, PFAS and Neurodevelopmental Disorder-Alcohol Exposed (ND-AE). This latter group includes individuals with severe CNS abnormalities without the physical features of FAS. This is the group the 4-Digit-Code calls Static-Encephalopathy-Alcohol-Exposed (SE-AE). The criteria for FAS, PFAS, and ND-AE (or what the 4-Digit-Code calls SE-AE) are identical between the Australian and 4-Digit-Code guidelines with the exception of one very small, but very consequential difference in facial criteria for PFAS. The 4-Digit-Code requires a Rank 3 FAS facial phenotype for PFAS (J Popul Ther Clin Pharmacol20(3):e416-e467, 2013); the Australian guidelines relax the criteria to include the Rank 2 FAS facial phenotype. This relaxation of the criteria renders the facial phenotype NOT specific to prenatal alcohol exposure as confirmed in published empirical studies. If the facial phenotype is not specific to (caused only by) prenatal alcohol exposure one can no longer validly call the outcome PFAS. When one makes a diagnosis of FAS (full or partial), one is stating explicitly that the individual has a syndrome caused by prenatal alcohol exposure. One is also stating explicitly that the biological mother drank alcohol during pregnancy and, as a result, harmed her child. These are bold conclusions to draw and are not without medical, ethical, and even legal consequences. So the question remains-Why go against the published empirical evidence and relax the PFAS facial criteria into the normal range?