To diagnose cancer during pregnancy is a terrible event for the patient and her family and a complex situation for physicians. The management of this clinical situation should be as standardized as possible, most similar to management that would be offered without pregnancy. Except in rare cases, termination of pregnancy is not justified by the cancer itself, because it does not improve the prognosis. Hormone therapy, targeted therapy, chemotherapy in the first trimester, and radiotherapy are most of the time contra-indicated. During the 2nd and 3rd trimesters, management will follow the usual recommendations with surgery and chemotherapy. The delivery term depends on the date of discovery of cancer but is beyond 35 weeks of gestation in the majority of cases. It is at best scheduled between the oncologist and obstetrician to minimize fetal or obstetrical risks. A network exists to help physicians and patients: www.cancer-et-grossesse.fr.