The diameter and morphology of polycaprolactone (PCL) nanofibers were optimized by varying electrospinning conditions including applied voltage, concentration of PCL solution, feed rate, and spinneret-collector distance, to obtain smooth and bead-free nanofibers. Scanning electron microscope (SEM) and Fourier-transform infrared spectroscopy were used to characterize the obtained nanofibers. The results revealed that smooth, bead-free PCL nanofibers were acquired at an applied voltage of 20 kV, polymer concentration of 10.0 m/v %, feed rate of 0.5 mL h-1, and spinneret-collector distance of 15.0 cm. SEM image show continuos uniform and smooth surface fibrous structure of electrospun PCL fibers with average diameter of 170.87nm.This demonstrated the synergistic effect of optimizing multiple electrospinning parameters on the diameter and morphology of PCL nanofibers.