Sulfotransferase 1A1 (SULT1A1), also designated as phenol-preferring sulfotransferase, is involved in the bioactivation and detoxification of a variety of potential carcinogens, including iodothyronines, hydroxylated aromatic amines, and phenolic xenobiotics. A common arginine (R) to histidine (H) polymorphism at amino acid position 213 influences SULT1A1 activity and has been suggested as risk factor for a different types of cancers. To investigate the role of this polymorphism for breast cancer risk, SULT1A1 genotype was determined in 500 women with clinically verified breast cancer and 500 female age-matched healthy control subjects. Frequencies of heterozygous (controls: 42.5% patients: 50.2%) or homozygous (controls: 12.6%; patients: 9.4%) carriers of the 213H variant were not significantly different between groups. The SULT1A1 genotype was furthermore not associated with tumor size, histological grading, estrogen or progesterone receptor status and age at diagnosis. The SULT1A1 213H variant was associated with the presence of lymph node metastases (p = 0.002). We conclude that the SULT1A1 R213H polymorphism is not a general risk factor for breast cancer, but may be involved in lymph node metastazing in breast cancer patients.