Conducting polymers demonstrate low solubility in organic solvents. Introducing aliphatic substituents into polymer chains improves their solubility, but may also lead to changes in conformational characteristics of macromolecules. In the present work, the studies of hydrodynamic properties and conformational characteristics of comb-shaped poly(3-hexylthiophene) with aliphatic side substituents were carried out in chloroform solutions. Conformational analysis of the studied macromolecules was performed for the first time using homologous series in a wide range of molecular weights of the polymer in dilute solutions. Hydrodynamic properties of macromolecules were interpreted using the worm-like spherocylinder model (Yamakawa H.) and the straight spherocylinder model (Norisuye T.) The length of a monomer unit projection onto the extended macromolecule (λ = 0.37 nm) was determined experimentally. The following parameters were characterized quantified: equilibrium rigidity (А = 6.7 nm) and hydrodynamic diameter o