Significant progress has been made in the diagnosis of seborrheic dermatitis. It is based on the anamnesis and clinical picture of skin lesions. Carrying out a detailed analysis of the structure and size of the body in combination with clinical and instrumental studies allows us to further make a more reliable prognosis of complications of this disease and improve the results of treatment of such patients. The aim of the study was to establish and analyze the features of the skinfold thickness in Ukrainian men and women with seborrheic dermatitis of varying severity. Skinfold thickness (SFT) was determined in 40 men and 40 women (aged 25 to 44 years) with generalized fatty seborrheic dermatitis (mild and severe). The control group consisted of SFT values of practically healthy men (n=82) and women (n=154) of the same age group from the database of the research center National Pirogov Memorial Medical University, Vinnytsya. Statistical processing of SFT indicators was performed in the license package “Statistica 6.0” using non-parametric evaluation methods. Compared with practically healthy men, patients with mild and severe seborrheic dermatitis had lower SFT values on the posterior (by 49.7 % and 46.5 %) and anterior (by 41.9 % and 46.4 %) surfaces of the shoulder and chest (by 28.9 % and 27.9 %), on the thigh (47.3 % and 38.3 %), on the forearm (only compared to severe severity by 18.5 %), at the lower angle of the shoulder blade (only compared to mild severity by 3.5 %) and on the shin (only compared to severe severity by 15.9 %), as well as higher values of SFT on the side (by 36.7 % and 51.6 %); and in women patients of varying severity– also lower values of SFT on the posterior surface of the shoulder (by 51.0 % and 43.6 %), on the anterior surface of the shoulder (by 46.6 % and 31.0 %), on the chest (by 31.3 % and 18.9 %), on thighs (by 47.4 % and 38.9 %) and on the shin (only compared to the mild degree by 10.2 %), as well as higher values of SFT on the side (by 37.0 % and 44.6 %). Among men or women with seborrheic dermatitis of varying severity, only higher values were found in women with severe SFT on the anterior surface of the shoulder (by 22.6 %), and in men with severe severity – higher values of SFT on the thigh (by 14.6 %). Manifestations of sexual dimorphism of SFT among patients with seborrheic dermatitis of varying severity were found only between men and women with severe disease, namely, higher values of SFT in women on the front shoulder surface (by 28.6 %), forearm (by 16.0 %) and on the shin (by 26.3 %).