We have developed a tele-medicine system to monitor the airway status at home for patients with poorly controlled asthma, whereby a nurse provides instructions to individuals via the telephone to help them manage exacerbation under the supervision of their physicians. We examined the effectiveness of this system with a randomized control study. Patients with high hospitalization risk were enrolled in the study by screening patients for those with multiple previous emergency room visits and randomly assigned to either the tele-medicine or control group. After six months of participation in the program, the number of emergency room visits decreased significantly and the activities of daily living were improved in the tele-medicine group. Most of the patients in the tele-medicine group were able to continue measuring and transmitting peak expiratory flow (PEF) value successfully, and at six months had noticed an improvement in PEF. We therefore conclude that the system effectively contributes to the management of poorly controlled asthma. In addition, further consideration suggests that the reduction of emergency room visits may lead to reduction in hospitalization since we found a good correlation between number of emergency room visits and hospitalization from the studies published previously.