A study was conducted on the grain of mountain rye (Secale montanum) to estimate its basic physical properties and chemical composition. The initial experimental material originated from Turkey and was multiplied in Poland by the authors. Determinations of physical properties of the grain included bulk porosity, bulk density, weight of 1000 kernels, angles of repose and of slide, and individual kernels, after measurements of thickness and length, were subjected to strength testing. The scope of chemical analyses included determination of the content of the basic nutrients, dietary fibre fractions, amino acids, fatty acids, and mineral components. It was found that the values that characterise grain in bulk were higher for that species as compared to standard rye cultivars. Similarly, higher indexes were obtained for most of the strength parameters of single kernels. Chemical analysis revealed that grain of mountain rye Secale montanum had a typical content of nutrients given for rye Secale cereale in nutrition standards, with a slightly lower content of dietary fibre fractions and lysine, and a higher content of methionine, unsaturated fatty acids (linoleic and linolenic) and zinc.