The anatomical dimensions of the internal organs are relatively stable and constitutionally determined. The connection between the somatotype and the size of the internal organs in adolescents - boys and girls - remains virtually unexplored. So, the purpose of this work is to compare the size of the internal organs separately in the group of young men and girls with lepto-, meso-and hypersome somatotype. The study involved 421 teenagers aged from 13 to 17 years: 225 boys and 196 girls. Their somatotypes were determined according to the patented method of V.A. Melnik, I.I. Salivon, N.I. Polina, and the sizes of abdominal organs and thyroid gland were determined using ultrasound morphometry. Their comparisons revealed the mosaic distribution of differences in the size of internal organs in children with different types of constitution. The authors discussed possible reasons of this difference: a methodological error in visualizing the size of internal organs, the influence of thyroid hormones, general biological and evolutionary factors, and the effect of narrow (in terms of gender and age) selection of the subjects. Thus, an orientation towards the constitutional features of the organism as a factor influencing the results of ultrasound examination of internal organs should be optional until the mechanisms and structure of these features are clarified in detail.