In order to define specific constitutional features of the children infected with tuberculosis 222 children in the age from 1 to 14 years old have been examined: 106 children with active tuberculosis; 54 children with remaining post-tuberculosis changes; 62 children infected with tuberculous mycobacteria. The following types of diatheses were identified: lymphohypoplastic, allergic, neuroarthritic, exudative-catarrhal. It has been found out that among those with active tuberculosis the children suffering from lymphohypoplastic and neuroarthritic diatheses prevail (17.0 ± 3.7%), and allergic diathesis is less common (10.4 ± 3.0% cases). Children with lymphohypoplastic diathesis have a complicated course of tuberculosis (27.8 ± 10.6%) and more intensive intoxication syndrome (55.6 ± 11.7%). The frequency of allergic diathesis is higher in the children with remaining post-tuberculosis changes (29.6 ± 6.2%) and those infected with tuberculosis (33.8 ± 6.1%) compared to children with active tuberculosis (10.4 ± 3.0%).