To evaluate the association between HER2 codon 655 polymorphism and breast cancer risk in this meta-analysis. A comprehensive search was performed to identify all case-control studies investigating such association. Statistical analyses were conducted with software MIX 1.54. Twenty eligible reports, including 10,642 cases/11,259 controls, were identified. In overall analysis, the Val allele frequency in cases was significantly higher than that in controls (OR = 1.0921, 95% CI: 1.0013-1.191, P = 0.0466), while no associations were found in both recessive and dominant models. In subgroup analysis, HER2 codon 655 polymorphism was weakly associated with breast cancer risk in recessive (OR = 2.4624, 95% CI: 1.0619-5.7104, P = 0.0357), dominant (OR = 1.2781, 95% CI: 1.0353-1.5779, P = 0.0225), and co-dominant genetic models (OR = 1.2947, 95% CI: 1.0682-1.5693, P = 0.0085) in Asian population, respectively. Meanwhile, the susceptibility to breast cancer in people aged < or =45 was significantly increased in both recessive (OR = 2.2408; 95% CI: 1.2876-3.8998, P = 0.0043), and dominant models (OR = 1.2902, 95% CI: 1.1035-1.5085, P = 0.0014). No significant associations were observed in Caucasian, European, and Family history subgroups. So our analyses suggest HER2 codon 655 Val allele is weakly associated with an increased risk of breast cancer, and SNP at HER2 codon 655 could be considered as a susceptibility biomarker for breast cancer for Asian females or women age 45 years or younger.