It was revealed that the main component of the studied samples composition of the essential oil of Nigella is monoterpene p-cymene, the content of which is ~ 60 %. According to the results of the study of the fatty acid composition of the seed lipids of the studied samples, the prevalence of omega-6 (linoleic) and omega-9 (oleic) unsaturated fatty acids was found (75.11–76.91 % of the total fatty acid content). Samples of NP-13/2 (sum of omega-acids 77.56 %, linoleic acid content – 60.16 %) and NP-4 (sum of omega-acids 77.55 %, oleic acid content – 18.12 %) are promising. In the process of studying the amino acid composition in seed extracts, four essential (leucine, methionine, valine, threonine) and four essential (arginine, proline, serine, glycine) amino acids were identified. A promising sample was NP-13/4 (the sum of amino acids is 62.23 %, the arginine content is 17.56 mg/kg, the leucine is 4.95 mg/kg, and threonine is 4.12 mg/kg). The obtained data testify to the value of using not only ecologically and geographically distant forms, but also samples of hybrid origin of nigella sown, selected and adapted to the conditions of Belarus, as source material in breeding work when creating varieties of medicinal purpose.