Breast cancer, the most common cancer in women, is a leading cause of cancer death among women worldwide. Obesity is associated with increased risk of breast cancer. Discovery of biomarkers that can be used for diagnosis, prognosis, and predictors of breast cancer is very important. Visfatin, a new adipokine found in visceral fat, plays a main role in metabolic and stress responses. There is an association between elevated expression of visfatin with malignant behavior and adverse prognosis in breast cancer. Visfatin promotes malignancy via signaling pathways that include Ras, Raf, MEK1/2, ERK, phosphoinositide 3-kinase (PI3K), Akt, and NF-κB. Visfatin up-regulates G1- S phase cell cycle progression through up-regulation of mRNA levels of cyclin D1 and CDK2. Visfatin plays a main role in metastasis and synthesis of genes that play a significant role in tumor-related angiogenesis such as vascular endothelial growth factor, progression and tumor invasion such as matrix metalloproteinases in cancer. Visfatin may increase breast cancer cell growth and metastasis capability through c- Abl and STAT3 activation (two oncoproteins). According to the results of these studies, visfatin expression appears to be associated with virulent behavior and its inhibition may be an effective treatment for breast cancer patients.