Homogeneous and fairly monosized microspherical structures of polyaniline has been synthesized using a simple soft template method with beta-naphthalene sulfonic acid (beta-NSA) as both the surfactant and dopant, and ammonium persulfate (APS) as the oxidant at 2-5 degrees C. The morphology of PANI-NSA was successfully controlled from nanotubes to microsphere, by changing the synthesis conditions (i.e. pH, the concentration of surfactant and monomer, and temperature). Some mechanistic aspects of the formation of nanotubes and hollow spheres have been discussed precisely based on SEM, TEM, DLS, FTIR and UV-visible results. Moreover, synthesis was performed under acidic environment to obtain further understanding about the formation mechanisms. (C) 2013 Elsevier Ltd. All rights reserved.