Background: Although there are some methods to detect cardiac arrhythmias like 24-hours holter monitoring or event recorder, long-term monitoring especially for the patients who have a very rare event has many limitations. Implantable loop recorder also has limitations because it only could be performed by surgical procedure. Recently, advancement of mobile network systems has lead to development of wireless mobile cardiac monitoring system. The aim of this study was to evaluate the usefulness of wireless mobile cardiac monitoring system. Methods: From 2009 to 2010, a total of 70 patients who could not be diagnosed with conventional monitoring system like 24-hours holter monitoring were enrolled in this study. Wireless mobile cardiac monitoring was performed for these patients. The electrocardiographic signals were recorded by small patch attached to the front of chest. The signals were transmitted to mobile phone by wireless system. The electrocardiograms recorded by mobile systems were transmitted to a web server of mobile center, and all the recordings were saved and evaluated. Results: Of the 70 patients, 2 patients were diagnosed with sick sinus syndrome which was confirmed by sinus pause recorded at monitoring system. One of the 2 patients was treated by permanent pacemaker implantation. 2 patients were diagnosed as ventricular tachycardia and treated by medication successfully. 1 patient was diagnosed with supraventricular tachycardia and received radiofrequency catheter ablation. There were also 4 patients who diagnosed as symptomatic premature ventricular contraction and treated with medication successfully. Conclusions: Wireless mobile cardiac monitoring system showed usefulness in detecting cardiac arrhythmias especially for the patients who had difficulty in diagnosis because of a very rare event.