【Abstract】 Objective To compare the effectiveness and accuracy of the Cerebral State Index (CSI) and the Bispectral Index (BIS) in monitoring the depth of anesthesia during laparoscopic renal surgery. Methods A total of 101 patients undergoing laparoscopic renal surgery were simultaneously monitored with CSI and BIS. Anesthesia was induced with intravenous propofol and maintained with sevoflurane inhalation. CSI and BIS values were recorded at various time points: at rest with eyes closed (T0), at the start of propofol injection (T1), at the loss of consciousness (T2), before tracheal intubation (T3), after tracheal intubation (T4), at the start of sevoflurane inhalation (T5), at the beginning of surgery (T6), after insufflation of the abdominal cavity (T7), at the end of pneumoperitoneum (T8), at the cessation of sevoflurane inhalation (T9), at the end of surgery (T10), at the recovery of consciousness (T11), before extubation (T12), after extubation (T13), and upon leaving the operating room (T14). Results No differences were observed between the two indices at T0, T3, T6 to T9 (all P 0.05), while at T2 and T4, CSI was consistently lower than BIS (all P 0.05), and at T1, T5, T10 to T14, CSI was lower than BIS (P 0.01). Significant differences in the two indices were noted around the time of loss and recovery of consciousness (T1 to T2 and T10 to T11) and before and after extubation (T12 to T13) (all P 0.01); however, no statistical significance was found before and after the establishment and conclusion of pneumoperitoneum (T6 to T7 and T7 to T8) (all P 0.05); interaction effects were not statistically different (all P 0.05). According to Bland-Altman consistency analysis, during the anesthesia induction period (T1 to T5) and the recovery period (T10 to T14), the mean differences between BIS and CSI were 3.7 (95% CI 2.5 to 4.9) and 5.8 (95% CI 4.9 to 6.7), with Limits of Agreement (LOA) of -25.3% to 32.8% and -13.7% to 25.5%, respectively, indicating a statistically significant difference (P 0.01); during the maintenance of anesthesia (T6 to T9), the mean difference was -0.2 (95% CI -1.4 to 0.9), with LOA of -24.2% to 23.6%, showing no statistical significance (P = 0.6461). Through ROC curve analysis, the AUC for BIS and CSI monitoring the state of unconsciousness during the induction of anesthesia were 0.937 (95% CI 0.894 to 0.966) and 0.845 (95% CI 0.7884 to 0.8926), respectively, with optimal cutoff values of 83.50 (sensitivity 90.1%, specificity 90.1%) and 75.50 (sensitivity 85.1%, specificity 72.3%). During the recovery from anesthesia, the AUC for BIS and CSI monitoring the recovery of consciousness were 0.955 (95% CI 0.9168 to 0.9793) and 0.929 (95% CI 0.884 to 0.960), with optimal cutoff values of 73.5 (sensitivity 90.1%, specificity 87.1%) and 62.5 (sensitivity 90.1%, specificity 82.2%). Conclusion During the induction and recovery periods of anesthesia, BIS values were higher than CSI values and the two indices showed good agreement during the maintenance of anesthesia. Both indices demonstrated satisfactory monitoring and predictive capabilities for conscious changes.