Sodium fl uoroacetate (1080) is a vertebrate pesticide used for controlling fi eld populations of introduced pest mammals in New Zealand and Australia especially. There have been scientifi c and public concerns over the potential for adverse environmental effects of 1080 use. To address one recent concern, an investigation of the potential endocrine-disrupting effects of 1080 and its active metabolite fl uorocitrate was conducted using in vitro assays. Binding of 1080 and fl uorocitrate to rainbow trout brain and human androgen (AR) and alpha oestrogen receptors (ER) was assessed. Neither 1080 nor fl uorocitrate had any effect on ER or AR binding with any of the bioassays employed. Accordingly, 1080 and fl uorocitrate are considered unlikely to promote androgenic, anti-androgenic, oestrogenic or anti-oestrogenic effects by binding to the ER or AR.