It is well known that substituted thiosemicarbazides are widely used in medical practice, as anticancer, antimicrobial, antituberculous, antifungal and other drugs. In many cases, the biological activity of these substances is in good agreement with their structure. Therefore, the synthesis and study of the structural features of the new thiosemicarbazide derivatives have the scientific and practical interest.  In this work we present the results of determination of structural features of N-(2,3-dimethylphenyl)hydrazinecarbothioamide (I), and N-(3,5-dimethylphenyl)-hydrazine-carbothioamide (II). The molecule of I is not planar. The dihedral angel between aromatic cycle and SCNN-group is 85.3 while in II it is equal to 7.2º. In the crystals of I-II the molecules form the centrosymmetic dimers which are held together by hydrogen bonds.