Aim: To study the correlation between partial CO2 rebreathing method (RBCO) and transesophageal Doppler (TECO) for perioperative cardiac output (CO) monitoring in neurosurgical patients. Methods: Twenty-nine scheduled for craniocerebral surgery were selected from the Department of Anesthesiology, Beijing Tiantan Hospital Affiliated to Capital University of Medical Sciences during March and December 2003. After endotracheal intubation induced by anesthesia, breathing apparatus was connected to perform intermittent positive pressure ventilation. Intraoperative CO changes in the 29 neurosurgical patients at the time points of the beginning of surgery, cranial drilling, bone flap craniotomy, dura mater shearing, tumor-taking out, hemostasis and the end of surgery were simultaneously measured with partial RBCO and TECO. The correlation between the two methods of partial RBCO and TECO were analyzed with linear regression method. Results: A significant correlation was found between RBCO and TECO for CO monitoring (r = 0.78, P < 0.01). The regression equation is RBCO = 0.88 TECO + 0.63. Conclusion: RBCO used for CO monitoring is easily and simply operated without trauma to the neurosurgical patients. There is a good correlation between cardiac outputs measured with RBCO and TECO.