Polyaniline doped with CSA/PEO conductive nanofibers were produced by electrospinning. The electrospinning window was determined by using a three level, full factorial experimental design. The combined effects of the humidity, voltage and flow rate on the fiber morphology and diameter were examined demonstrating that the ambient humidity is the critical factor affecting the electrospinning process and determining the electrospinning window for a conductive polymer. Low humidity favors the formation of defect free fibers while high humidity either hinders fiber formation or causes the formation of defects on the fibers either due to jet discharge or due to water absorption and phase separation. High level of doping with CSA led to the formation of crystalline structures. Data fitting was used to explore the behavior of conductive polymers in electrospinning and very good agreement between experimental and theoretical predictions was obtained for only a limited range of experimental conditions, whereas deviation was observed for all other sets of conditions. (C) 2015 Published by Elsevier Ltd.