Objective: To study the association of BRCA1 promoter methylation with rs11655505 (c.-2265C/T) variants and gene expression in sporadic breast cancer. Methods involved SNP analysis, methylation-specific PCR and gene expression evaluation from paraffin-embedded tissues. Results: Promoter methylation was significantly associated only with estrogen receptor status. Genotypic and allelic frequencies were not significantly different from controls. Decreased BRCA1 expression was associated with CT genotype and with methylation in tumor samples. Conclusion: SNP rs11655505 and BRCA1 methylation are not significantly associated with sporadic breast cancer occurrence, but methylation is linked to reduced gene expression in tumors. © 2012 FESEO. © 2014 Elsevier B.V., All rights reserved.