Electrically conductive polyaniline (PANI) and its blend with polycarbonate (PC) was prepared by one-step emulsion polymerization technique in which sodium lauryl sulfate (SLS) acts as surfactant and as a protonating agent for the resulting polymer. The prepared PANI and its blends were characterized by density, percentage of water absorption, and electrical conductivity. PANI-PC blend exhibits a conductivity value of 4.70 x 10(-2) S/cm (PANI-PC1) and 5.68 x 10(-5) S/cm (PANI-PC3) with a change in dopant from p-toluene sulfonic acid (TSA) to SLS, respectively. By using a more general method, which takes into account the presence of disorder of the second kind in polymers proposed by Hosemann, crystal size () and lattice strain (g in %) values were estimated. The variation of conductivity in doped PANI and PANI-PC blend has been explained on the basis of these microcrystalline parameters. TGA thermograms of PANI and PANI-PC blend show three-step degradation behavior. Thermal stability of PANI was improved after blending with PC.