Sixty-seven children with proven gastroesophageal reflux had preoperative gastric emptying assessed using 99Technetium-Sn-colloid labelled milk. Delayed gastric emptying was defined as a gastric residual activity of more than 40% at 2 hours after feeding. The antireflux operation was a partial anterior fundoplication. Postoperative milk scans assessed the effect of surgery on gastric emptying.