Positive airway pressure (PAP) devices are used to treat patients with sleep related breathing disorders (SRBD) including obstructive sleep apnea (OSA). Currently, PAP devices come in three forms: (1) continuous positive airway pressure (CPAP), (2) bilevel positive airway pressure (BPAP), and (3) automatic self-adjusting positive airway pressure (APAP). After a patient is diagnosed with OSA, the current standard of practice involves performing full, attended polysomnography during which positive pressure is adjusted to determine optimal pressure for maintaining airway patency. This titration is used to find a fixed single pressure for subsequent nightly usage. A task force of the Standards of Practice Committee of the American Academy of Sleep Medicine reviewed the available literature. Based on this review, the Standards of Practice Committee developed these practice parameters as a guideline for using CPAP and BPAP appropriately (an earlier review and practice parameters for APAP was published in 2002). Major conclusions and current recommendations are as follows: 1) A diagnosis of OSA must be established by an acceptable method. 2) CPAP is effective for treating OSA. 3) Full-night, attended studies performed in the laboratory are the preferred approach for titration to determine optimal pressure; however, split-night, diagnostic-titration studies are usually adequate. 4) CPAP usage should be monitored objectively to help assure utilization. 5) Initial CPAP follow-up is recommended during the first few weeks to establish utilization pattern and provide remediation if needed. 6) Longer-term follow-up is recommended yearly or as needed to address mask, machine, or usage problems. 7) Heated humidification and a systematic educational program are recommended to improve CPAP utilization. 8) Some functional outcomes such as subjective sleepiness improve with positive pressure treatment in patients with OSA. 9) CPAP and BPAP therapy are safe; side effects and adverse events are mainly minor and reversible. 10) BPAP may be useful in treating some forms of restrictive lung disease or hypoventilation syndromes associated with hypercapnia.