Pregnancy – associated breast cancer is a breast cancer diagnosed during pregnancy or the lactation period up to first postpartum year. Most common histopathological type is invasive ductal carcinoma. Majority of tumors are highly differentiated, hormone independent and they invade surrounding lymph vessels. Most common diagnostic imaging procedures during pregnancy are mammography and ultrasound. Patient’s stage of disease, gestational age, development of the fetus and the preferences of the patient and family needs to be taken into consideration for the selection of the most appropriate therapy. Breast surgery can be safely performed during all trimesters of pregnancy. Radiation is contraindicated because of the feta exposure to radiation. Chemotherapy is prescribed during second and third trimester and it is contraindicated during the first trimester of pregnancy because of the risk of teratogenicity. Most common used protocol is FAC – protocol which consists of 5 – fluorouracil, doxorubicin and cyclophosphamide because of the minimal risk to the fetus or the infant. Chemotherapy should not be given after the 35th week of gestation in order to minimize the risk of neutropenia in mother and newborn during and after the delivery. Hormone therapy, if indicated, is given after the delivery and after chemotherapy. Tamoifen is not recommended during pregnancy because of the risk of teratogenicity. There is no need for different kind of prenatal care of fetus in patients with breast cancer. Therefore, fetus can be monitored with standard prenatal care. If chemotherapy is planned to continue after the delivery, vaginal delivery is recommended because of the lesser complications comparing to cesarean section. Breastfeeding during radiation and chemotherapy is contraindicated.