The benefit of water protocols for individuals with thin-liquid aspiration remains controversial, with mixed findings from a small number of randomized controlled trials (RCTs). This study aimed to contribute to the evidence of the effectiveness of water protocols with a particular emphasis on health outcomes, especiallyhydration. An RCT was conducted with patients with known thin-liquid aspiration post-stroke randomized to receiving thickened liquids only or a water protocol. For the 14 participants in rehabilitation facilities whose data proceeded to analysis, there was no difference in the total amount of beverages consumed between the water protocol group (mean=1103ml per day, SD=215ml) and the thickened liquids only group (mean=1103ml, SD=247ml). Participants in the water protocol group drank on average 299ml (SD 274) of water but offset this by drinking less of the thickened liquids. Their hydration improved over time compared with participants in the thickened liquids only group, but differences between groups were not significant. Twenty-one percent of the total sample was diagnosed with dehydration and no participants in either group were diagnosed with pneumonia. There were significantly more diagnoses of urinary tract infection in the thickened liquids only group compared to the water protocol group (χ 2 =5.091, p=0.024), but no differences between groups with regard to diagnoses of dehydration (χ 2 = 0.884, p=0.347) or constipation (χ 2 =0.117, p=0.733). The findings reinforce evidence about the relative safety of water protocols for patients in rehabilitation post-stroke and provide impetus for future research into the potential benefits for hydration status and minimizing adverse health outcomes.Drinking, deglutition, deglutition disorders, stroke, water, water-electrolyte imbalance [6]. The premise is that thickening a liquid makes it more cohesive and dense, reducing its flow rate. This enables many patients to better control the bolus intra-orally, thereby reducing aspiration risk before and during swallowing [7,8].There has been growing concern, however, about the blanket prescription of thickened liquids for a number of [14,18,19]. By far the greatest concern about thickened liquid prescription is that individuals with dysphagia do not consume enough fluids. Researchers have demonstrated that the bioavailability of water from a quantity of thickened liquids is equivalent to that from the same quantity of thin liquid [20][21][22] confirming that thickened liquids themselves are not the cause of dehydration. Furthermore, it is recognised that, in addition to beverages, food contributes to approximately 20% of overall fluid intake with an even greater percentage if individuals are on pureed food [23,24]. Notably, food was found to be the greatest contributor to oral fluid intake in a cohort of patients with dysphagia in acute settings [25]. However, total fluid intake has consistently been found to be inadequate for individuals with dysphagia on modified diet and liquids, especially if reliant o...