The World Health Organization (WHO) reported that 18.1 million people were diagnosed with cancer and 9.6 million people died in the latest data from 2018. With the increase in diagnostic possibilities, more people are diagnosed with cancer and as a public health problem; it has led to more treatment options being investigated in this field. The most common types of cancer in the world are lung, prostate, stomach, and liver in men, while the most common types are breast, lung, cervix, and colon cancer in women. In 2018 WHO report, it was stated that 2.09 million women were diagnosed with breast cancer. Attention is drawn to the importance of new treatment options considering these rates and the fact that it is the most common type of cancer in women (1, 2).The application of radioisotope and radiopharmaceutical therapies in many cancer treatments [thyroid (3), gastrointestinal system (4), prostate (5), gastroenteropancreatic, lung (6), non-Hodgkin lymphoma ( 7), cancers such as prostate bone metastases (8), breast bone metastases (9)] and positive results obtained have directed researchers to preclinical studies about the applicability of these treatment methods to breast cancer.These treatments aim to directly target cancerous cells and protect healthy tissue. Radionuclide therapy (RT) involves sending radioactive elements with different emission properties into cancerous tissue. RT has the advantage of delivering a highly concentrated dose to the targeted tumor tissue while protecting the normal tissues surrounding the tumor tissue. The fact that these treatment practices are minimally invasive and the duration of treatment is shorter than chemotherapy has made them one of the most preferred cancer treatment methods recently (10).Radiopharmaceutical treatments (RPT) are carried out by sending radionuclides conjugated to tumor-targeted pharmaceuticals or bioactive molecules (nanoparticles, antibodies, peptides, small molecules, and various structures of each) that predominantly accumulate in neoplastic cells within tumors into the tumor tissue (11). Recently, RT has attracted attention as a safe and effective method for cancer treatment, and research continues (12).In this review article, the effectiveness of preclinical studies conducted in the last five years with radionuclides and radiopharmaceuticals in breast cancer will be discussed.