Objective: Serum AMH level has been shown to decrease in women treated for breast cancer in several studies. However, whether basal AMH status affects AMH dynamics during chemotherapy remains to be clarified. The objective of this study was to compare serum AMH dynamics in young women with either low, normal or high basal serum AMH level at diagnosis, during and after treatment with chemotherapy for breast cancer. Study design: In this secondary analysis of a prospective cohort study, serum AMH was measured during and after chemotherapy in 239 women of reproductive age diagnosed with breast cancer and treated with chemotherapy. The association between AMH dynamics throughout chemotherapy and during follow-up and basal AMH status, i.e. low AMH (<1 μg/l, <7 pmol/l), normal AMH (1-4.9 μg/l, 7-36 pmol/l) and high AMH (≥5 μg/l, >36 pmol/l), was evaluated. Menses occurrence was also recorded. Results: A total of 21 women had low, 154 had normal and 64 had high basal AMH level. Serum AMH rapidly decreased during chemotherapy in all groups, and its variation during chemotherapy and follow-up was not significantly different between the 3 groups. Conclusion: No association was found between AMH variation during chemotherapy and follow-up, and basal AMH level at diagnosis. However, women with high basal AMH levels have significantly higher AMH levels throughout chemotherapy and follow-up than women with normal or low basal AMH levels at diagnosis.