Purpose This study aimed to evaluate the uptake of fertility preservation, rate of pregnancy, pregnancy outcome and breast cancer outcome after diagnosis of early breast cancer in young women who were referred to Maastricht University Medical Center, from the regional hospitals in the Southeast part of the Netherlands. Patients and methods We prospectively registered the demographics of patients, who visited our university hospital for counseling on fertility preservation at diagnosis of stage I-III invasive breast cancer in the years 2008-2015. At baseline, tumor and treatment characteristics were registered. During follow-up information on fullfilled childwish and disease status was collected. To compare the fertility preservation group and the non-fertility preservation group independent samples Student t-tests and Chi-square tests were conducted. Results In total 128 women with a median age of 32 years (19 – 43) were referred for fertility preservation counseling before start of chemotherapy, with an increase in referral in the more recent years. Thirty-nine (30.5%) women chose for fertility preservation: in 26 patients embryos were frozen, in seven oocytes, and in one both embryos and oocytes. In four patients the procedure was not succesfull. Patients who had chosen for fertility preservation more often had a male partner (87.2% vs 70.8%, P = 0.05) and had a smaller tumor size (median 19 versus 23 mm, P = 0.04) at the time of diagnosis compared to those who did not chose for fertility preservation. During a median follow-up of 30.3 months (range 0 – 96.9), 27 (21.1%) patients had tried to conceive: 14 (35.9%) women in the fertility versus 13 (14.6%) in the non-fertility preservation group. All of these had recovery of ovarian function after chemotherapy-induced ovarian failure. Only two women used the cryopreserved embryos, both succesfully and combined with preimplantation genetic diagnosis of the embryos because of germline mutations in BRCA1-gene. Eight patients in the fertility preservation group and seven patients in the non-fertility preservation group became at least once pregnant. In the fertility preservation group, eight healthy babies were born, one baby had Morbus Hirschsprung, one women is pregnant at this moment and one woman had a miscarriage. Of the eleven pregnancies in the non-fertility preservation group, nine healthy babies were born and one woman had two miscarriages. Of the referred 128 women, nine (7.0%) had breast cancer recurrence, three in the fertility preservation group versus six in the non-fertility preservation group. Conclusion One third of referred patients choose for fertility preservation before start of chemotherapy. In all of these patients, the ovarian function recovered. However, two couples used their cryopreserved embryos for preimplantation genetic diagnosis and both became pregnant. Since the follow-up time is relatively short, more data are mandatory to make a statement on the effectiveness of fertility preservation techniques in young breast cancers patients. Citation Format: Vriens IJ, Butalid EM, Schepers-van der Sterren EE, van der Poel MH, Jansen-Engelen SL, van Riel A-MM, van de Wouw YJ, Vriens BE, van Haaren ER, Lemaire BM, Dercksen WW, Luiten EJ, de Boer M, de Die-Smulders CE, Derhaag JG, van Golde RJ, Tjan-Heijnen VC. Preserving fertility in young women undergoing chemotherapy for early breast cancer; the Maastricht experience [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD6-03.