This chapter presents a recent review on the preparation of conducting polypyrrole (pPy) in conventional medium and ionic liquid medium. Moreover, a new greener methodology for the in-situ electrochemical synthesis of pPy on gold electrode using room temperature ionic liquid 1-butyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl) imide is also reported. The pPy modified electrode was utilized for the detection of chemical warfare agent simulant thiodiglycol. Bare gold and pPy modified gold disc electrodes were characterized in-situ by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) and ex-situ by Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). SEM images of pPy modified gold electrode exhibited small irregular shaped humps with wrinkled boundaries. Moreover, Raman spectroscopy and EDAX results confirmed the presence of pPy on gold surface. EIS analysis of the pPy modified electrode exhibited acceleration of charge transfer due to the formation of conducting polymer on gold surface. pPy modified gold disc electrode showed good electrochemical activity with the simulant of sulfur mustard thiodiglycol. This chapter is divided into following three parts (a) Conducting polymers prepared using Ionic Liquids and their applications [review] (b) Conducting polymers prepared using conventional aqueous and nonaqueous medium and their applications [review] and (c) Greener electrochemical synthesis of a conducting polymer and its application in chemical agent simulant sensing [new unpublished report]. © 2011 by Nova Science Publishers, Inc. All rights reserved.