Breast cancer is the second most common cause of cancer-related mortality among women. Despite all the improvements so far, especially, failure to fully treat advanced breast cancer could be attributed to late diagnosis of disease and also the application of biopsy techniques that require surgical procedures for diagnostic purposes that lead to great difficulty to the patient. For these reasons, clinically important new biomarkers, which can be obtained easily and cheaply with reliable, minimal and non-invasive techniques and can be used in the early diagnosis, treatment and follow-up of the patient are of great importance. In this line, recent studies have focused on one of the most significant components of liquid biopsy technique known as circulating tumor DNA (ctDNA). ctDNA has the potential to be used as biomarker that enables the detection of genetic alterations in cancer cells in real-time for target treatment of breast cancer. In this review, the potential role of ctDNA in the diagnosis, prognosis, and the management of breast cancer patients will be summarized including general information on breast cancer diagnosis, cancer & liquid biopsy and importance of ctDNA together with recent researches evaluated on this timely topic.