The present study explored the ways to prepare thickened liquids of different consistencies using lotus root starch (LRS) powder and evaluated their efficacy in treating post-stroke dysphagic patients. Thickened liquids matching the four consistency levels advocated by the International Dysphagia Diet Standardization Initiative (IDDSI) guidelines were prepared. To assess their clinical applicability, 76 post-stroke dysphagic patients were randomly divided into three groups: a xanthan gum (XG) group (n=26), an LRS group (n=26), and a control group (n=24). All groups received an intervention including swallow-related exercises and oral feeding training. The control group used regular foods (water, juice, congee, egg custard, and banana puree), while the XG and LRS groups used their respective thickened liquids. Swallowing performance was assessed before and after the intervention using the Standardized Swallowing Assessment (SSA), Penetration-Aspiration Scale (PAS), and gastric tube use duration and removal rate, incidence of adverse reactions, and cost of thickening associated with the three groups were obtained after intervention. While all groups experienced a significant improvement after the intervention, as indicated by the SSA and PAS scores, the XG and LRS groups demonstrated significantly better outcomes than the control group. In addition, the XG and LRS patients had shorter gastric tube use, greater removal rate, and fewer incidence of adverse reactions than the controls. The cost of XG was greater than that of LRS powder for the intervention. LRS powder can be used to prepare thickened liquids of different consistencies following the IDDSI framework. Its efficacy and safety in treating dysphagia are comparable to XG based thickeners. However, seeing its markedly lower cost, LRS powder can be considered a viable alternative to XG based commercial thickeners.