INTRODUCTION: The efficacy and safety of the rapid intravenous rehydration (RIR) guidelines in children affected by dehydration secondary to acute gastroenteritis is supported by current scientific evidence, but there is also great variability in its use in clinical practice. OBJECTIVE: To prepare a document with evidence-based recommendations about RIR in paediatric population. METHODS: The project was developed based on GRADE methodology, according to the following work schedule: Working Group training; creation of a catalogue of questions about research and definition of «relevant outcomes¼; score and selection criteria for each item; bibliographic review; scientific evidence evaluation and synthesis (GRADE); review, discussion and creation of recommendations. 10 clinical questions and 15 relevant outcomes were created (7 about efficacy and 8 about security). RESULTS: Sixteen recommendations were set up, from which we can highlight as the main ones: (1) RIR is safe for children affected by mild-moderate dehydration secondary to acute gastroenteritis, unless expressly contraindicated or acute severe comorbidity (strong recommendation and moderate evidence). (2) Its use is recommended in this situation when oral rehydration has failed or due to contraindication (strong and high). (3) Isotonic fluids are recommended (strong and high), suggesting saline fluid as the first option (light and low), supplemented by glucose (2.5%) in those patients showing normoglycemia and ketosis (strong and moderate). (4) A rhythm of 20 cc/kg/h is recommended (strong and high) during 1-4 h (strong and moderate). CONCLUSIONS: This document establishes consensus recommendations, based on the available scientific evidence, which could contribute to the standardisation of the use of RIR in our setting.