Background: Non-invasive ventilation (NIV) is an efficient method for treating respiratory failure in patients with amyotrophic lateral sclerosis (ALS). However, it requires a process of adaptation not always achieved due to poor compliance. The role of telemonitoring of NIV is not yet established. Objectives: To test the advantage of using modem communication in NIV of ALS patients. Design: Prospective, single blinded controlled trial. Population and methods: According to their residence, 40 consecutive ventilated ALS patients were assigned to one of two groups: a control group (G1, n=20) in which compliance and ventilator parameter settings were assessed during office visits; or an intervention group (G2, n=20) in which patients received a modem device connected to the ventilator. The number of office and emergency room visits and hospital admissions during the entire span of NIV use and the number of parameter setting changes to achieve full compliance were the primary outcome measurements. Results: Demographic and clinical features were similar between the two groups at admission. No difference in compliance was found between the groups. The incidence of changes in parameter settings throughout the survival period with NIV was lower in G2 (p<0.0001) but it was increased during the initial period needed to achieve full compliance. The number of office or emergency room visits and inhospital admissions was significantly lower in G2 (p<0.0001). Survival showed a trend favouring G2 (p=0.13). Conclusions: This study shows that telemonitoring reduces health care utilisation with probable favourable implications on costs, survival and functional status.