The Epworth Sleepiness Scale (ESS) has been recognized as a valid measure of sleep propensity. Statistically significant correlations between ESS scores, the respiratory disturbance index (RDI), and the lowest arterial oxygen saturation (LSAT) have been described in patients with surgically untreated obstructive sleep apnea (OSA). We investigated whether the same relationships hold true after uvulopalatopharyngoplasty (UPPP). Forty-two adults with documented OSA treated by UPPP were reevaluated with the ESS questionnaire and 8-hour diagnostic nocturnal polysomnography (nPSG). We found no significant correlation between the ESS scores and the RDI or LSAT in patients after UPPP. Because postoperative ESS scores do not correlate with the RDI or LSAT, we conclude that the ESS is not a reliable surrogate for nPSG testing.