Imitating animal-based products using plant-based raw materials is a technological challenge due to the different technological and functional properties of the proteins. In plant-based hollandaise sauce s, the egg yolk is often replaced with carbohydrate-based thickeners, although vegetable proteins such as legumes also have the potential as structuring agents. This study addresses the techno-functional properties of legume protein isolates (soy, pea and lupin) and their use in a vegetable-based hollandaise sauce. The flow properties of the sauces were characterized using the rotational rheometry. The Herschel-Bulkley function was fitted to the flow curves and one-factor ANOVA and Tukey-Kramer post-hoc-test were applied to analyse theresults . Concerning the functional properties, it is noticeable that the protein isolates bind more water than oil except for lupin. The emulsion activity index increased mostly because of the heating step (65 °C). Moreover, oil interferes foaming and lupin shows a significantly higher foam capacity. All sauces show shear thinning behavior. The Herschel-Bulkley model represents a good approximation. The Herschel-Bulkley parameters are not affected by the different heating steps. The results show that vegetable proteins, such as legumes are quite suitable as a structuring ingredient in hollandaise sauce products, but further experiments are necessary to make more precise statements.