Fasting time before procedural sedation and analgesia in a pediatric emergency department (ED) was recently reported to have no association with the incidence of adverse events. This study further investigates preprocedural fasting and adverse events. Data were analyzed from a prospectively generated database comprising consecutive sedation events from June 1996 to March 2003. Comparisons were made on the incidence of adverse events according to length of preprocedural fasting time. Two thousand four hundred ninety-seven patients received procedural sedation and analgesia. Four hundred twelve patients were excluded for receiving oral or intranasal drugs (n=95) or for receiving sedation for bronchoscopy by nonemergency physicians (n=317). A total of 2,085 patients received parenteral sedation by emergency physicians. Age range was 19 days to 32.1 years (median age 6.7 years); 59.9% were male patients. Adverse events observed included desaturations (169 [8.1%]), vomiting (156 [7.5%]), apnea (16 [0.8%]), and laryngospasm (3 [0.1%]). Fasting time was documented in 1,555 (74.6%) patients. Median fasting time before sedation was 5.1 hours (range 5 minutes to 32.5 hours). When the incidence of adverse events was compared among patients according to fasting time in hours (0 to 2, 2 to 4, 4 to 6, 6 to 8, >8, and not documented), no significant difference was found. No patients experienced clinically apparent aspiration. No association was found between preprocedural fasting and the incidence of adverse events occurring with procedural sedation and analgesia.