This study was conducted to develop a statistical understanding of exposures to bisphenol A (BPA) in aquatic environments in North America and Europe. Concentrations of BPA have been reported by 89 investigations published between 1997 and 2007. On the basis of an analysis of weighted observations (n = 1068 and 848 for North America and Europe, respectively), BPA was reported at concentrations above the detection limit in 20-51% of freshwater samples. Median BPA concentrations for fresh surface waters for North America and Europe were 0.081 and 0.01 microg/L, respectively, while 95th percentiles were 0.47 and 0.35 microg/L, respectively. In contrast to fresh surface waters, only limited data are available for sediments and less for marine ecosystems. For freshwater sediments in North America (n = 71), the median and 90th percentile concentration (the 95th percentile was not calculable) were 0.6 and 3.4 ng/ g-dw, respectively, while the median and 95th percentile concentration in Europe (n = 249) were 16 and 256 ng/g-dw, respectively. To assess the potential ecological significance, we compared exposure concentrations with available regulatory criteria. The results suggest the frequency of locations in which concentrations are likely to cause adverse effects on aquatic ecosystems is low, with the exception of sediments collected from some highly urbanized and industrial locations.