Background: Although breast cancer is more commonly diagnosed in post-menopausal women, there are a significant number of survivors diagnosed at age 45 or younger. Compared to older survivors, younger survivors have significantly more problems with depression sexual functioning, marital satisfaction, and overall well-being, but there is little research on the partners of these younger survivors. The purpose of this study is to determine if the partners of young survivors experience more problems with depression, sexual functioning, marital satisfaction, and overall well-being than partners of age-matched controls. Methods: Survivors and partners (n=227) were enrolled in a large cross-sectional study, executed through the ECOG-ACRIN Cancer Research Group. Eligibility for survivors included being 45 or under at diagnosis, 3 to 8 years from treatment without a breast cancer recurrence, and with similar chemotherapy treatment regimens. Survivors identified age-matched acquaintance controls without breast cancer. These age matched controls and their partners (n=170) were also included. All groups completed a survey assessing demographic characteristics, depression, sexual functioning (enjoyment and difficulty), marital satisfaction, and overall well-being. The partners of both young survivors and acquaintance controls were compared on all study variables adjusting for demographic variables. Results: Partners of young survivors reported significantly more depression (effect size [ES] = -0.23, p=.0199), worse sexual functioning as indicated by lower enjoyment (ES= 0.32, p=.0019) and more sexual difficulty (ES= -0.24, p=.0164), lower marital satisfaction (ES=0.24, p=.0189), and lower overall well-being (ES= 0.40, p=.0001). Conclusions: Partners of breast cancer survivors suffer from problems similar to breast cancer survivors. Further research is needed to fully understand the impact of a breast cancer diagnosis on both the partner as well as the survivor, especially when problems exist that are related to the dyadic relationship.