Acrylamide, a probable human carcinogen, is formed during high-temperature cooking of many commonly consumed foods. It is widespread; approximately 30% of calories consumed in the United States are from foods containing acrylamide. In animal studies, acrylamide causes mammary tumors, but it is unknown whether the level of acrylamide in foods affects human breast cancer risk. The authors studied the association between acrylamide intake and breast cancer risk among 90,628 premenopausal women in the Nurses' Health Study II. They calculated acrylamide intake from food frequency questionnaires in 1991, 1995, 1999, and 2003. From 1991 through 2005, they documented 1,179 cases of invasive breast cancer. They used Cox proportional hazards models to assess the association between acrylamide and breast cancer risk. The multivariable-adjusted relative risk of premenopausal breast cancer was 0.92 (95% confidence interval: 0.76, 1.11) for the highest versus the lowest quintile of acrylamide intake (P(trend) = 0.61). Results were similar regardless of smoking status or estrogen and progesterone receptor status of the tumors. The authors found no associations between intakes of foods high in acrylamide, including French fries, coffee, cereal, potato chips, potatoes, and baked goods, and breast cancer risk. They found no evidence that acrylamide intake, within the range of US diets, is associated with increased risk of premenopausal breast cancer.