Buckwheat (Fagopyrum sagittatum Gilib) is a very valuable cultivated plant which is used in human feeding to produce groats and flour, its green matter is used as animal feed, its leaves are applied to obtain rutin and it is also a honey plant. Botanically, the buckwheat seed is a triangular nutlet which is deprived of seed cover in the process of groats production. Whole roasted and not roasted groats, broken roasted groats and buckwheat porridge (broken, not roasted) are obtained during buckwheat processing. During groats production, apart from seed husking, seeds are also classified according to their size. The process is applied repeatedly, before and after the seeds husking, after cutting and polishing. Therefore, the aim of the work was to determine the geometric parameters for whole nutlets and seeds after their husking. The studies were carried out on Red corolla, a new form of buckwheat that, besides the red perianth, is characterized by better resistance to low temperatures and drought in comparison to presently cultivated varieties. The whole nutlets were weighed exactly to 0.001 g, then lateral surfaces and cross-section areas were estimated by the optical reader LD 5.2. The same procedure was performed for seeds after husking. It was found that the buckwheat nutlet was a symmetrical and trihedral solid. The nutlet weight amounted to 10.7-40.8 mg and the husk content in the whole seed weight amounted to 24.0-35.0%. Lateral surfaces of the whole nutlets hesitated between 12.61 and 29.55 m2, while those of seeds after husking between 6.35 and 14.67 m2. Similar lateral surfaces of nutlets were found when the smallest lateral surface was assumed as 100% and then the following surfaces would amount to 103 and 104% for the whole nutlets, and to 103 and 106% for the seeds after husking. Therefore, the contours of the lateral surfaces nearly overlapped. The obtained geometric parameters were presented in the weight function of Red corolla nutlets.