Compared to Ile (A) allele, significant increase in the risk of breast cancer was observed with Val (G) allele (OR, 2.21; 95% CI, 1.35–3.63; p-0.0016).We observed significant association between HER2 Ile655Val polymorphism and breast cancer risk under the dominant (OR = 2.52; 95% CI: 1.41–4.51; p-0.001) and codominant (OR, 2.24; 95% CI: 1.23–4.09; p-0.008) model, whereas no significant relationship was found under the recessive model (OR, 2.47; 95% CI: 0.63–9.57; p-0.190). The gene discussed is ERBB2; the disease is breast carcinoma.