The book, entitled "The Rheology of Vegetable Oils Used as Biodegradable Lubricants," is structured in three chapters and presents a study of olive, sunflower, rapeseed, and soybean vegetable oils that can be used as biodegradable lubricants.Chapter I presents the current state of research on the use of environmentally friendly lubricants based on vegetable oils and the physicochemical properties of these oils.Chapter II presents the rheological behavior of olive, sunflower, rapeseed and soybean oils by applying the rheological models found in the literature but also by finding other rheological models that accurately describe the behavior of vegetable oils at different temperatures and shear rates.Chapter III includes the application of the extended Vogel-Tammann-Fulcher equation to non-additive soybean oil but used as a biodegradable lubricant.