The first part of this paper presents the preparation and morphological studies of high surface area polypyrrole with fibrillar morphology. Mode of fibre growth within host membrane pores has been examined by ultra-microtome techniques. The rate of fibre growth in different solvents has been determined. The second part of this paper describes the formation of conducting composite membranes of polypyrrole with in-house prepared and commercial ("Biotran") microporous polyamides. The conducting polymer was chemically polymerized using several techniques in association with the membranes in these studies. Surface and cross-sectional membrane morphology was studied by high-resolution field emission scanning electron microscopy, optical microscopy and transmission electron microscopy. Environmental stability of composite membranes has been examined by measuring the conductivity as a function of time.