Successful attempts to produce high-molecular-weight polyanilines via electrochemical synthesis are reported. A systematic study of the influence of electropolymerization conditions on the weight-average molecular weight (M(w)) showed that M(w) of polyaniline varied only between about 22000 and 40000 g mol(-1), even for a wide range of conditions. Significant increases in M(w) are only obtained when a neutral salt is added to the electrolyte. M(w) can be increased up to 160000 g mol(-1) by increasing the LiCl concentration to about 6 M. This salt effect on M(w) is consistent with electrostatic charge screening effects.