Purpose Sexual quality of life (QoL) is affected during and after breast cancer (BC) treatment and is not specifically evaluated with the general health-related quality-of-life questionnaires EORTC QLQ-C30 or QLQ-BR23. A specific questionnaire, the EORTC SHQ-C22, including physical, psychological, and social aspects of sexuality, was recently developed to address this issue in cancer patients. Methods A prospective bicentric study was conducted to evaluate the sexual QoL of women with BC during the first year of adjuvant hormonal treatment. Results A total of 106 women completed the 3 questionnaires at baseline and 92 of them, at 12 months. At baseline, we showed low sexual satisfaction and importance given to sexual activity and a very low communication with healthcare professionals about this issue. Twelve months later, the importance given to sexuality had increased. While the communication with professionals had improved, it remained at a very low level. We were unable to identify specific clinical factors (chemotherapy, menopausal status, type of surgery or radiotherapy) that would negatively affect the global sexual well-being in BC patients. Conclusion The analysis of sexual QoL of BC patients during the first year of hormonal treatment with a recently developed, cancer-dedicated, standardized tool pointed out the need for deeper communication between professionals and patients regarding sexual issues to fill the current gap in care of cancer patients and help patients with adequate intervention and support.