Polyindole fibers upto a length of 1000 pm and similar to 25 mu m in diameter have been reproducibly synthesized by interfacial polymerization, which was performed at a stationary interface of aqueous (FeCl3 solution)/organic (indole in dichloromethane) biphasic system. On the other hand, disturbing the aqueous/organic interface by constant stirring of solution-termed as bulk polymerization-resulted in globular (average size similar to 2 mu m) polyindole. The results of Fourier transform infrared spectroscopy revealed that polymerization takes place at carbon atoms located at positions 2 and 3 in indole monomer, and this has explained origin of different polyindole morphology obtained in interfacial and bulk polymerization. Cyclic voltammograms recorded as a function of scan rate indicated a high electroactivity of the synthesized polyindole. (c) 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 595-599, 2007