In reviewing the research and conceptualization associated with battered woman syndrome in the work of Lenore Walker and other related empirical studies, this paper concludes that there are problems in the definition, conceptualization, and use of the syndrome, and substantial methodological deficiencies are noted in the key empirical studies upon which the syndrome is based. Additionally, the author questions whether expert evidence by psychologists is necessary on this issue in contemporary Australia, given that battered woman syndrome has not been sufficiently scientifically validated to be appropriately used in the forensic context in Australia. On the critically important forensic issue of distinguishing battered women with battered woman syndrome from the general category of battered women, the author concludes that no reliable criteria have yet emerged that would permit such categorization. She advises that it is clear that conceptual imprecision surrounding the battered woman syndrome does not permit the accurate diagnosis of women with this syndrome, thereby suggesting that the (as yet unknown) error rate associated with the diagnosis of battered woman syndrome would be unacceptably high. This article also challenges the contention that expert testimony on battered woman syndrome in criminal trials is necessary because the situation of battered women and the psychological effects of the abuse are beyond the knowledge and ordinary experience of judges and jurors. 22 notes, 113 references, and appended supplementary information