Abstract Despite the importance of oncofertility care in supporting women coping with fertility challenges after breast cancer, the practice of oncofertility care among nurses remains suboptimal. There is an urgent need to investigate oncofertility barriers faced by nurses caring for women with breast cancer. A cross-sectional online study was conducted among registered nurses caring for women with breast cancer. A self-developed questionnaire and the Oncofertility Barriers Scale (OBS) were used to assess participants’ characteristics and self-perceived barriers. A score ≥ 3 indicates a high level of oncofertility barriers requiring further attention. 372 nurses completed the survey, with 45.54% reporting a score of ≥ 3 on the OBS. Notably, 85% of participants reported high levels of barriers in at least one domain and 27.42% reported barriers in all six domains of the scale. The most commonly reported barrier was “Stereotype of cancer patients” (71%). Nurses without fertility training, those who did not read fertility-related guidelines, and those in departments lacking such guidelines reported significantly higher barriers (all p < 0.05). The prevalence of oncofertility barriers among nurses is high. Educational programs should be developed to address these barriers, improving the quality of oncofertility care for women with breast cancer.