The management of patients with breast cancer during their pregnancy is challenging. A good coordination is required between the oncology and obstetrics teams in order to ensure appropriate care, while providing a reassuring environment during this stressful period. Most often, the pregnancy can continue without delaying the initiation of oncological treatments, offering a prognosis similar to non-pregnant women. Surgery and chemotherapy can be done during pregnancy, unlike endocrine therapy, radiotherapy and antibody treatments which can only be given postpartum. While some imaging techniques are compatible, others require special measures or are contraindicated. We discuss these points in the context of a clinical situation.