The rotating jet electrospinning method has been modified to increase the amount and the degree of alignment of electrospun nanofibers. For this purpose, the cylindrical collector of the rotating jet method (RN) was replaced by two metallic concentric hollow cylinders. We called this improved technique; a modified rotating jet method (MRJM). The effectiveness of this method was evaluated with measuring the production rate and the degree of alignment of electrospun fibers and comparison of them with those obtained for the RJM. Our results disclosed that, the MRJM can improve the degree of alignment of electrospun fibers more than two times. Furthermore, when the voltage changed from 10 kV to 22 kV the average production rate of electrospun nanofibers was increased by 41% compared with the RJM. (C) 2010 Elsevier B.V. All rights reserved.