Proteins constitute a fundamental building element of all tissues in the human body and of many biologically active compounds, such as enzymes, hormones, and antibodies. Buckwheat grains are a source of the high quality proteins the amino acidic composition of which is well balanced. The content of proteins in buckwheat grains ranges from 8.5 to 19 % d.m. The objective of the investigations was to determine the effect of roasting process (temperature: 160 ºC, 30 min, moisture: 14.5 %) on the range of in vitro enzymatic digestibility of proteins. The proteins were isolated from dehulled grains of buckwheat prior to and after roasting. The analysis of the digestibility of buckwheat protein preparations conducted in an environment simulating physiological conditions of digesting proteins in duodenum proved that the roasting process applied had an effect of improving the digestibility of the examined proteins of buckwheat: 82.7 % – prior to roasting and 85.5 % – after roasting. However, the amount of isolated proteins considerably decreased in the preparation made of grains after the roasting process. While analysing the SDS PAGE images of proteins in grains prior to and after the roasting process, it was found that they contained essential amounts of two fractions: the one having a molecular mass of 22·10³ Da and the second of a molecular mass between 55·10³ and 32·10³ Da. However, as the result of the roasting process, the considerable degradation was reported of the fraction having a molecular mass of 55·10³ Da.