Advances in auto-adjusting positive airway pressure technology for obstructive sleep apnea now permit this treatment to be initiated outside of the sleep laboratory environment, bypassing the need for laboratory-based titration studies. Thus far, little research has addressed how such developments may affect compliance to continuous positive airway pressure (CPAP). We tested the effect of laboratory CPAP exposure and technologist support in a retrospective chart review of 98 veterans with obstructive sleep apnea to determine whether patients who received standard laboratory CPAP titration complied better with CPAP than did patients who received no laboratory CPAP titration. Fifty patients underwent standard technician-attended polysomnography (PSG) with CPAP titration, and 48 patients underwent unattended PSG with no laboratory trial of CPAP (first CPAP exposure was at home). Objective CPAP compliance measures were obtained from CPAP units at follow-up visits. Attended-PSG patients wore CPAP significantly longer per night on average (5.0 hours vs 3.9 hours) and tended to wear CPAP on more nights (76.5% vs 64.2%) compared with unattended-PSG patients. These findings suggest that patients' sleep laboratory experience with CPAP and the support and education provided by sleep technologists are important factors in facilitating CPAP compliance.