No study has reported an association between gastroesophageal reflux disease (GERD) or its therapies and gallbladder function. We compared pre- and postoperative gallbladder function in patients undergoing fundoplication to determine the following: (1) whether patients with chronic GERD have preexisting gallbladder motor dysfunction; (2) whether medical or surgical therapy alters gallbladder function; and (3) whether division of the hepatic branch of the anterior vagus nerve is detrimental to gallbladder motility. Nineteen patients with documented GERD consented to a preoperative cholecystokinin-stimulated technetium hepatobiliary (CCK-HIDA) scan to quantify the gallbladder ejection fraction (GBEF). All patients underwent laparoscopic Nissen fundoplication. One month after fundoplication, 12 patients completed a repeat CCK-HIDA scan for determination of GBEF, with comparison to the preoperative GBEF. Among patients with preoperative GERD, 11 (58%) of 19 met the scintigraphic criteria for gallbladder dysfunction (GBEF <35%), which is a ratio comparable to that in patients undergoing a CCK-HIDA scan for presumed biliary dyskinesia during the same time period (31 [60%] of 53; P = NS, chi-square test) and exceeds the rate of abnormal GBEF reported in healthy volunteers (3%). Six of seven patients with a low preoperative GBEF who underwent repeat evaluation postoperatively had normalization of the GBEF (P < 0.05, paired t-test). In the 12 patients who underwent postoperative CCK-HIDA scanning, there was no association between preservation or division of the hepatic branch of the anterior vagus nerve and postoperative gallbladder dysfunction (P = NS, chi-square test). Unexpectedly, 58% of patients with GERD demonstrated gallbladder motor dysfunction prior to fundoplication, with improvement to normal occurring in most of those studied postoperatively. These data support controlled trials to determine the effect of chronic GERD and antisecretory therapy on gallbladder and global gastrointestinal smooth muscle function. Preservation of the hepatic branch of the anterior vagus nerve during fundoplication offered no clear benefit with regard to early postoperative gallbladder function.