Objective To investigate the effects of pulmonary resection on right ventricular function in patients with lung cancer. Methods Forty-seven patients with lung cancer undergoing pulmonary resection were divided into lobectomy group (n=32) and pneumonectomy group (n=15). Real-time three-dimensional echocardiography were preformed before operation, 3 d and 8 d after operation to obtain the data of right ventricular end-diastolic volume index (RVEDVI), right ventricular ejection fraction (RVEF), mean pulmonary artery pressure (mPAP) and heart rate (HR), and arterial oxygen pressure (PaO₂) was monitored simultaneously. Results Three days after operation, mPAP, HR and RVEDVI significantly increased, and RVEF significantly decreased in two groups (P<0.05), and the changes were more significant in pneumonectomy group. PaO₂ after operation was significantly lower than that before operation in pneumonectomy group (P<0.05), while the decrease in PaO₂ after operation was not statistically significant in lobectomy group (P>0.05). Eight days after operation, all parameters recovered to those before operation in lobectomy group, while there were still significant differences between all parameters before operation and those after operation in pneumonectomy group (P<0.05). Conclusion Right ventricular function may decrease after pulmonary resection, especially in patients treated by pneumonectomy. Sleeve resection of bronchus and pulmonary artery is recommended instead of pneumonectomy to achieve the better outcome.