Background In Western countries, factors contributing to breast cancer presentation delay have been identified, but little is known about presentation delay in China, where culture and healthcare systems are quite different. Objective To describe the delay interval among newly diagnosed breast cancer patients in China and to identify factors influencing delay, including the COVID-19 pandemic. Methods Using a cross-sectional design, we recruited 154 participants within 3 months of pathological diagnosis of breast cancer. Data were collected using standardized scales and open-ended questions. Results We found 44.8% of participants delayed ≥1 month, and 24.7% delayed ≥3 months before presentation, after self-discovery of symptoms. Logistic regression analysis showed that factors associated with longer delay (≥1 month) included preferring female physicians for breast examination, fewer negative emotions (afraid, anxious, distressed) regarding breast symptoms, more competing priorities, believing folk therapy can help treat lumps, and visiting a secondary or tertiary hospital instead of primary healthcare providers ( P < .05 for all). Interaction tests showed perceived seriousness of symptoms significantly predicted delay of ≥1 month only when perceived healthcare access or trust in physicians was low. Patients (14%) reported delaying due to fear of COVID-19 infection and inability to leave home. Conclusions Presentation delays were substantial and multilevel barriers to timely presentation were identified, which would be expected to contribute to later-stage cancer at diagnosis. Implications for practice Findings suggest that nursing interventions and improved health policies are urgently needed in China, including breast cancer education to increase awareness.