Obesity is the main risk factor for several sleep breathing disorders, including obstructive sleep apnea syndrome (OSAS), either alone or associated with chronic obstructive pulmonary disease (COPD), and alveolar obesity-hypoventilation syndrome (AOHS). In several of these conditions, the indicated treatment includes the use of non-invasive ventilation during sleep, such as the use of continuous positive airway pressure (continuous positive airway pressure or CPAP) and two-level pressure (BIPAP, bi-level positive airway pressure). In this chapter, a brief review is made of what the most recent studies say regarding the treatment of SOHA with non-invasive ventilation (NIV), comparing different ventilation modes and/or treatments.