Electrospinning is one of the techniques to produce non-woven fiber mats using polymers. The diameters of the fiber produced by this technique are in the range of 10 ^m to 10 nm. Electrically conducting ultra fine fibers are useful in many applications in the fields of sensors, and nanoelectronics. However, it is very difficult to obtain fibers of conducting polymers like polyaniline (PANI) and polypyrrole through electrospinning. Hence they are invariably mixed with other insulating polymers such as polymethylmethacrylate (PMMA) to obtain a conducting composite depending on the percolation of the conducting polymer. Here, we report the preparation of PANI-PMMA composite fibers by electrospinning. The scanning electron micrographs and the frequency dependent complex conductivity (σ*(ω)) of these polymer fibers are investigated at room temperature with different concentrations of PANI (5%, 10%, 15%, 20% w/w). It is observed that there is a significant enhancement in the ac conductivity of these fibers with the increase in the concentration of PANI.