Digestibility of food grade modified starches were examined by the controlled enzymatic hydrolysis with the mixture of pancreatic alpha-amylase and glucoamylase. The structure and physicochemical properties of the experimental starch samples were examined by the Brabender rheological method, light microscopy, and X-ray diffractometry. It was found that investigated food grade modified starches revealed reduced digestibility-up to about 10%. The extent of decrease of digestibility depends on the degree of substitution of modified starches, but this correlation is not linear. Granular food grade modified starches reveal unchanged crystal structure, identical as native starch. The modification of starch changes its physicochemical properties i.e. pasting profile, gelatinisation temperature and solubility in water, however these changes do not correlate with digestibility. Changes in conformation of starch macromolecules in solution, caused by incorporation of modifying groups, hinder enzymatic action of amylases and cause a drop in digestibility of starch.