The efficacy of continuous airway positive pressure ventilation with a nasal mask mainly depends on the appropriateness of the effective positive pressure level. Conventionally, this level is determined from polysomnographic recordings using progressively increasing pressure levels to determine, the point where episodes of apnea, hypopnea and snoring regress in all sleep phases and in all body positions. Since the first description of this method, many other titration methods have been proposed. Some use sophisticated signals such as the analysis of respiratory exertion level or limitation of inspiratory flow to provide a more precise titration which is particularly useful in cases where the classical titration method is insufficiently effective. Inversely, simplified methods have been examined from an economic point of view. These methods do not require the presence of a technician in a specialized laboratory where the waiting list for diagnostic tests is often long. Recordings during naps or short nights have been proposed for the more severe cases. Likewise titrations during simple polygraphy recordings or with an autoCPAP device have been shown to be effective in one-night laboratory recordings. Much work remains to be done to determine the effectiveness of these methods when used in the patient's home as well the long-term effects.