Efficacy and tolerance of home non-invasive ventilation (NIV) must be assessed by using objective criteria (clinical evaluation, arterial blood gases, oxymetry, and research of side effects such as air leaks, skin problems, etc). In this article, we describe a procedure for long-term follow-up of home NIV. We also suggest an algorithm using available polygraphic tools to ascertain causes of NIV failure, in order to correct them.