Laser-assisted uvulopalatoplasty (LAUP) has been introduced as an alternative to uvuloplatopharyngoplasty for the treatment of snoring. Despite limited study, the use of this procedure has been expanded to include patients with obstructive sleep apnea syndrome. Although the potential cost-savings of performing sleep apnea surgery on an outpatient basis are self-evident, concern exists regarding the safety of this practice. In an effort to characterize the risk of performing LAUP on an outpatient basis, eight patients with mild or no sleep apnea were identified and intensively studied before and after the first stage of LAUP to cure snoring. Assessment included preoperative magnetic resonance imaging (MRI) scans, polysomnography, and videoendoscopy. Each of these diagnostic studies was then repeated between 48 and 72 hours after LAUP. Complete polysomnographic data were available for seven of the eight patients. The mean ( +/- SD) preoperative respiratory disturbance index (RDI) was 11.3 +/- 10.9, and the mean oxygen saturation nadir (LSAT) was 87.7 +/- 6.2% (n = 7). The mean airway cross-sectional area at the palate (by MRI) was 49.8 +/- 22.8 mm2 (n = 8). After LAUP, the mean RDI nearly doubled to 21.7 +/- 9.9 (P > .1). The apnea index increased fourfold from 3.3 +/- 3.5 to 14.8 +/- 10.9 (P < .03). The mean LSAT remained stable at 87.4 +/- 4.1% (P > .5). The cross-sectional area of the airway decreased to a mean of 47.9 +/- 22.4 mm2 (P > .5). These data suggest that LAUP may temporarily worsen obstructive sleep apnea. Although the clinical significance of this degree of worsening is uncertain, it would be prudent to consider perioperative use of nasal continuous positive airway pressure in patients with more than mild obstructive sleep apnea who undergo ambulatory LAUP.