The aim of the study was to assess the relationship between the shape of the anteriorposterior spinal curvature and body composition in schoolchildren. The study included 257 children, aged 11-12. Correct spinal curvature was established in 106 (41.08%) subjects. Other types included: decreased kyphosis and correct lordosis-40 participants (15.50%), correct kyphosis and decreased lordosis-24 individuals (9.30%), increased kyphosis and correct lordosis-17 subjects (6.59%), correct kyphosis and increased lordosis-22 children (8.53%), decreased kyphosis and decreased lordosis-32 people (12.40%), decreased kyphois and increased lordosis-four of the examined subjects (1.55%) increased kyphosis and lordosis-13 people (5.04%). In addition, 134 (51.94%) demonstrated scoliotic posture and eight (3.10%) scoliosis. There were significant relationships between the shape of the anteriorposterior curvatures and body composition in schoolchildren. Those with a strong body build (predominance of mesomorphs) were generally characterised by the correct formation of these curvatures. In contrast, lean subjects (with the predominance of ectomorphic factors) were more likely to experience abnormalities. No correlations with body composition were observed in the group with scoliotic posture or scoliosis. Both in the prevention and correction of postural defects, one should gradually move away from one-sided, usually one-system, therapeutic effects. An approach that takes into account both somatic and neurophysiological factors seems appropriate. With the correct body composition and structure, shaping the habit of correct posture is much easier.