Lately, the problem of the food protein deficiency increased across the world, even in developed countries, due to the overpopulation and the popularity of vegetarian life style. In order to solve this problem, new productive and resistant plant varieties are needed, but the content of valuable proteins in grains must be as well a priority. The induced mutagenesis is widely used in creating of new varieties with desirable traits around the world. For the gamma ray induced mutagenesis, chickpea, soybean and peanut seeds of varieties created for R. Moldova were used: for chickpea - the Ichel variety; for soybean - the Alina and Zodiac varieties; and for peanut – the Kovarskii 17 variety were used. The doses applied for chickpeas were of 300 Gy, for soybeans - 250 Gy and for peanuts - 300 Gy. These doses were determined as semi-lethal for these varieties and are recommended for gamma ray mutagenesis for these crops. The gamma ray treatment was performed in an ionizing device - PXM-γ-20, supplied with Co60 isotope. As a result, a number of chickpea, soybean and peanut mutant varieties have been selected, for different valuable traits, for example: larger grains, higher number of grains per plant, higher number of internodes per plant and increased resistance to negative environmental factors etc. In order to determine the protein content in grains, 10 mutant varieties for each crop were studied. The reserve protein content in grains was determined by the Bradford method. In chickpeas, the protein content in grains of the control (Ichel variety) constituted 19.1%. Among the studied mutants, 2 of them exceeded the control: the F31 mutant variety exceeded the control by 11%, containing 21.3% of protein in seeds, and the F43 mutant exceeded the control with 15%, containing 22.4% proteins in the seeds. The other mutant varieties had almost the same protein content or even lower than the control. In soybeans, 2 controls were used - the Alina variety with a protein content of 34.63%, and the Zodiac variety with a protein content of 35.78%. Among the studied mutant varieties, 2 of them exceeded the control by protein content in seeds A3M7150 with a content of 35.91% (+ 3.7%) and Z1M6200 with a content of 38.46% (+ 7.49%). For other mutants, the protein content was lower than that of the control - for example, for the Z2M7250 mutant there were only 32.12% protein in seeds, which was with 10.2% less than in the control and the A1M6150 mutant had a protein content of 29.94%, which is with 13.34% less than the control. For peanuts, the control has 25.9% protein in the grains, 2 of the studied mutant varieties exceeded control: the M91 mutant variety having a content of 28.52% protein in seeds, which exceeded the control by 10%, and M124 with 27.86% protein in seeds, which exceeded the control by 7.5%. Other mutant varieties had protein content close to or even less than the control. The protein content in seeds of the chickpea, soybean and peanut mutant varieties induced by gamma ray mutagenesis varies in a wide range, from 3-7% for soybean up to 15% for chickpea compared to the initial varieties, used for mutagenesis.