ObjectiveTo investigate the clinical efficacy and safety of carvedilol in the treatment of arrhythmia in patients with hypertension complicated with diabetes mellitus. MethodsWe selected the patients with hypertension complicated with diabetes mellitus who were hospitalized in the Harrison International Peace Hospital Affiliated to Hebei Medical University for treatment from Oct. 2011 to Oct. 2013. The cases were divided into a trial group and a control group. The control group was given routine treatment (eg., hypoglycaemic drugs, angiotensin converting enzyme inhibitors). On the basis of the same treatment of the control group, the trial group was given carvedilol. The efficacy and adverse reaction were observed, recorded and then analyzed between the two groups. ResultsA total of 140 patients were included (70 cases in each group). With the loss of 10 cases in the control group, the data of 70 cases in the trial group and 60 cases in the control group were finally analyzed. The results showed that the trial group was superior to the control group in the total effectiveness (χ2=8.320, P=0.004) and the dynamic ECG improvement of premature ventricular contraction (χ2=5.333, P=0.014) with significant differences. Both groups were significantly improved in blood pressure and heart beats compared with the situation before treatment (Both P < 0.05), and the trial group was better than the control group with a significant difference. During the treatment, three cases in the trial group had mild gastrointestinal symptoms which spontaneously disappeared later. ConclusionThe clinical effectiveness of carvedilol for arrhythmia in patients with hypertension complicated with diabetes mellitus is significant. It is safe and effective which is recommended in clinical application.