Factors affecting on properties of nanofibers fabricated by electrospinning have especially been favored due to fact that electrospun nanofibers are used readily in many areas with different objectives. In this study, effects of applied voltage on morphologies of electrospun nanofibers containing polyvinylalcohol and sodium alginate were investigated. A constant volume of the feeding solutions was delivered to the needle at a flow rate of 3 ml/h and high potentials in the range of 28 kV-45 kV were applied as they exit the needle. The electrospun fibers were collected on the aluminum foil connected to the ground. The electrical conductivity measurements of feeding solutions were performed at room temperature. The morphology of electrospun fibers was investigated by the scanning electron microscopy (SEM) analysis. The broken nanofibers were obtained at 28 kV, whereas increasing the voltage to 35 kV or higher nanofibers appeared to be continuous without any significant change in diameters. As a result junctions of fibers decreased with voltage while the size of the beads increased with it. There was no clear correlation between the applied voltage and diameters of fibers, suggesting the effect of voltage may depend on other parameters such as gap distance and eventually the shape of the electric field. © 2011 Chamber of Turkish Electric.