The authors evaluated dietary predictors of concentrations of 11 polychlorinated biphenyls (PCBs) in breast adipose tissue from 190 women with benign breast disease who live in Ontario, Canada. Consumption of fish was positively correlated with, and the most consistent dietary predictor of, breast tissue PCB levels. Dietary predictors accounted for < 8% of the variation in breast adipose tissue PCB levels. Age was positively and most strongly associated with tissue PCB levels, perhaps representing long-term dietary intake and the complex interplay of absorption, metabolism, distribution, and excretion.