OBJECTIVE: Accumulation of estrogenic compounds and other carcinogens in normal breast tissues contributes to unpredictable breast cancer incidence during adolescence and throughout life. To assess the role of parabens in this phenomenon, the paraben content of adjacent normal-malignant breast tissues is measured in women with breast cancer living in Isfahan Province, Iran. METHODS: Adjacent normal-malignant breast tissue samples were obtained from 53 subjects. The parabens including methyl-paraben (MePB), ethyl-paraben (EtPB), propyl-paraben (PrPB), and butylparaben (BuPB) were extracted from the sample supernatant and then subjected to gas chromatography analysis. RESULTS: Some risk factors for breast cancer were stimulated by parabens in adjacent malignant-normal breast tissues among young and middle-aged women with breast cancer. We observed a significant association for dose-response pattern of MePB [OR = 98.34 (11.43-185.2), P = 0.027] for both ER+ and PR+ women and MePB [OR = 164.3 (CI: 112.3-216.3), P < 0.001] for HER2+ women than women with negative receptors. The risk of 95-fold increase in MePB dose and 164-fold increase in ΣPBs dose were significant for women with hereditary breast cancer in first-degree relatives. CONCLUSION These results may promote future epidemiology studies and strategies to improve women's lifestyle and consume paraben-free products.