Résumé : Background: Fertility and pregnancy-related issues are major concerns for young breast cancer patients. Limited data are available on physicians’ knowledge, attitudes and practice in these fields. Methods: A 26-item questionnaire exploring 3 different topics (fertility preservation, pregnancy after breast cancer and breast cancer during pregnancy) was sent by email to physicians attending the 2016 3rd European School of Oncology (ESO) – European Society for Medical Oncology (ESMO) Breast Cancer in Young Women Conference (BCY3) and the 15th St. Gallen International Breast Cancer Conference 2017 (BCC 2017). Given the selected sample, survey respondents were expected to have a higher than average interest in the management of breast cancer patients. Descriptive analyses were performed. Results: A total of 273 physicians (105 at BCY3 and 168 at BCC 2017) completed the survey; 37.0%, 46.9% and 34.8% reported never having consulted the available international guidelines on fertility preservation, pregnancy after breast cancer and management of breast cancer during pregnancy, respectively. Up to 18.3% of respondents did not know if the different fertility preservation options were available in their country; 22.3% suggested that controlled ovarian stimulation should not be considered safe in patients with hormone receptor-positive disease. A total of 30.4% of respondents agreed or were neutral on the statement that pregnancy in breast cancer survivors may increase the risk of recurrence. Regarding breast cancer during pregnancy, 23.8% and 38.1% disagreed or were neutral on the statements that endocrine therapy and anti-HER2 agents should be avoided during pregnancy, respectively. Conclusions: Further educational initiatives are needed to improve physicians’ knowledge and adherence to available guidelines when addressing fertility and pregnancy-related issues in young breast cancer patients.