OBJECTIVE: To explore the correlation between heart rate variability (HRV), peripheral cytokines, anxiety and pain scores in patients with breast cancer (BC). METHODS: We collected blood samples from 100 BC patients and measured the concentrations of Interleukin 6 (IL-6), Interleukin 4 (IL-4) and Interferon gamma (IFN-γ). We collected the patients' 5-minute dynamic electrocardiograms and evaluated their anxiety and pain levels through the Anxiety Self-Rating Scale and the Short-Form McGill Pain Questionnaire (SF-MPQ) Scale. RESULTS: Compared with patients in the high HRV group, the low HRV group had lower IL-4 levels and higher IFN-γ/IL-4 concentrations. At the same time, the level of anxiety was also higher, but there was no significant difference in pain. Spearman correlation analysis showed that the normal-to-normal cardiac intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent normal-to-normal cardiac intervals (RMSSD), high frequency -HRV (HF-HRV) and IL-4 were positively correlated, SDNN and RMSSD were negatively correlated with IFN-γ/IL-4. HRV is negatively correlated with anxiety. Higher SDNN predicts higher IL-4 levels. CONCLUSION: Our results indicate that BC patients with low HRV are associated with higher levels of inflammation and anxiety. Therefore, the measurement of HRV may serve as an objective and non-invasive measurement method for monitoring the immune system and anxiety problems of BC patients.