Although there is considerable controversy regarding the role of race in the etiology of human disease, evidence suggests that breast cancers are racially distinct diseases. Clinical features and genetic alterations are different in Chinese women with breast cancer compared with white women. These differences are significant and may influence clinical care. In this review, we summarize the literature addressing genetic heterogeneity in Chinese women with breast cancer. Data support important variations in genes involved in tumorigenic pathways of DNA repair, steroid synthesis and receptor expression, apoptosis, immunity, inflammation, cell cycle control, cancer growth and metastasis, and growth receptor signaling. These genetic differences contribute to our understanding of the molecular origins of breast cancer and may accelerate the development of personalized disease prevention strategies.