Objective To evaluate the efficacy of modified electroconvulsive therapy (MECT) in the treatment of elderly depression and investigate its effect on heart rate and blood pressure. Methods A total of 70 elderly patients with depression undergoing MECT in the MECT center of our hospital in the year of 2013 were recruited in this study. Beside drug treatment, they all finished 6 times of MECT. Hamilton Depression Scale (HAMD) was used to assess the clinical symptoms before, and in 3 and 6 times after treatment. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were recorded before treatment, after anesthesia, and in 0, 30 and 60 min after convulsion. Results Significant differences were found in HAMD scores in all patients between pre-treatment and 3 or 6 times after MECT (all P＜0.01), with an efficacy of 80.0% and 95.7% respectively. Compared with pre-treatment, SBP and DBP were significantly decreased while HR increased after anesthesia (all P＜0.01); SBP, DBP and HR were significantly increased after convulsion (all P＜0.01) and in 30 min after convulsion (all P＜0.01). However, SBP, DBP and HR returned to the levels of pre-treatment in 60 min after convulsion (all P＞0.05). Conclusion MECT combined with drug treatment is effective in the treatment of elderly depression, with rapid onset and good efficacy, and is worthy of being widely applied in clinical practice. In the process of MECT, blood pressure is reduced after anesthesia, and then obviously rises with HR after convulsion, but all these indices return to the levels before treatment in 60 min after convulsion. Continuous monitoring should be carried out during the whole process.