Aim: To assess the anxiety levels of breast cancer patients during the COVID-19 pandemic. Materials & methods: A total of 298 patients completed the State-Trait Anxiety Inventory (STAI-S and STAI-T) and the Visual Analogue Scale for Anxiety (VAS) and VAS for Anxiety in COVID-19 (VAS-CoV). Results: 144 patients were in the high anxiety category for STAI-S, and 202 patients were in the high anxiety category for STAI-T. STAI-T score was significantly high in the metastatic group (p = 0.017). VAS-CoV score in the hormonotherapy group was significantly higher than in the no-treatment group (p = 0.023). There was a positive correlation between VAS-CoV and VAS levels (r = 0.708, p < 0.001), VAS-CoV and STAI-S and STAI-T scores (r = 0.402, p < 0.001; r = 0.185, p = 0.001, respectively), and a negative correlation between education years and STAI-T scores (r = -0.172, p = 0.003). Conclusion: The COVID-19 pandemic is related to high anxiety levels in breast cancer patients.