An electrochemical method for growing macroscopic fibers of electrically conductive poly(3-methylthiophene) is described. Single fibers of uniform diameter (approximately 0.1 to 0.7 millimeter) and length greater than 10 centimeters are grown in a capillary flow cell by electrochemical oxidation of the monomer, 3-methylthiophene. The shapes and diameters of the resulting fibers are determined by the fluid flow pattern in the cell. Straight fibers, sawtooth-shaped fibers, and fibers with tapered necks can be grown by varying the capillary shape.