Chemical composition of common wheat – Triticum aestivum ssp. vulgare Vill. Host., hard wheat – Triticum durum Desf., and spelt – Triticum aestivum ssp. spelta (L.) Thell grains was investigated. Total protein, wet gluten, fiber, ash, carbohydrates, falling number, macronutrients (phosphorus, potassium, calcium, magnesium), and microelements (copper, iron, manganese, zinc) were determined. Also standard deviation, variability and correlation coefficients were calculated. Hard wheat and spelt lines were characterized by much higher contents of total protein, wet gluten, and falling number value than common wheat; however, the highest protein concentration and falling number was recorded in grains of hard wheat. Common wheat was distinguished by low ash content and the highest carbohydrates level. Higher percentage of macronutrients and microelements in grains of spelt and hard wheat, as compared to common wheat, confirms the usefulness of these species for foodstuff production. Among the qualitative traits studied, content of carbohydrates appeared to be the least variable (cv = 2.2%), while the highest variability (cv = 31.1%) was shown by fat content. Significant correlations for the following trait pairs were observed: protein–gluten, protein–carbohydrates, fat–ash, fat–falling number, carbohydrates– gluten, and ash–falling number.