OBJECTIVES: We sought to survey emergency physicians in the United States regarding the management of pediatric dehydration secondary to acute gastroenteritis. We hypothesized that responses from physicians with dedicated pediatric training (PT), that is, board certification in pediatrics or pediatric emergency medicine, would differ from responses of physicians with no dedicated pediatric training (non-PT). METHODS: An anonymous survey was mailed to randomly selected members of the American College of Emergency Physicians and sent electronically to enrollees of Brown University pediatric emergency medicine listserv. The survey consisted of 17 multiple-choice questions based on a clinical scenario depicting a 2-year-old with acute gastroenteritis and moderate dehydration. Questions asked related to treatment preferences, practice setting, and training information. RESULTS: One thousand sixty-nine surveys were received: 997 surveys were used for data analysis, including 269 PT physicians and 721 non-PT physicians. Seventy-nine percent of PT physicians correctly classified the scenario patient as moderately dehydrated versus 71% of non-PT physicians (P = 0.063). Among those who correctly classified the patient, 121 PT physicians (58%) and 350 non-PT physicians (68%) would initially hydrate the patient with intravenous fluids. Pediatrics-trained physicians were more likely to initially choose oral or nasogastric hydration compared with non-PT physicians (P = 0.0127). Pediatrics-trained physicians were less likely to perform laboratory testing compared with the non-PT group (n = 92, 45%, vs n = 337, 66%; P < 0.0001). CONCLUSIONS: Contrary to established recommendations for the management of moderately dehydrated children, significantly more PT physicians, compared with non-PT physicians, follow established guidelines.