This work deals with preparation, characterization, and performance of electro-conductive yarns prepared by in situ chemical and electrochemical polymerization of pyrrole. Box-Behnken design in conjunction with response surface analysis has been used to study the electrochemical polymerization process. The effect of electrochemical process parameters on the electrical resistivity has been reported. Further, the electrical and electromechanical behaviour of the electro-conductive yarns thus produced has also been reported. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 455-462, 2012