Breast cancer (BC) is the second most common cause of cancer deaths among females. It caused by many predisposing factors. Early diagnosis of breast cancer favors the outcome of the disease. Recently, many studies demonstrated that microRNAs have emerging role in diagnosis and prognosis of breast cancer. microRNAs are small uncoding RNAs composed of about 23 nucleotides. miRNAs can affect breast cancer progression by regulation of cell growth and apoptosis. Our study aimed to assess the expression pattern of microRNA-329 (miRNA-329) in BC females and correlate it with the clinical stage of the disease also the potential of miRNA-329 in the diagnosis of BC.