Highly aligned electrospun micro- and nanoscale fibers and pseudowoven mats were produced via electrospinning by incorporating an auxiliary counter electrode to create an electric field of controlled geometry and magnitude. Two polymers were examined using this technique: a polyimide (CP2) and a biodegradable polymer, poly(glycolic acid) (PGA). Highly aligned electrospun CP2 fibers were on the order of 10 mu m in diameter, and fiber spacing in the Spun mats ranged between 25 and 30 mu m. Electrospun PGA aligned fibers were on the order of 500 run in diameter with spacing between fibers ranging from 7 to 10 mu m in the spun mats. High-speed videography illustrated the influence of the auxiliary electrode on the elimination of jet whipping and bending instability commonly associated with the electrospinning process. The data presented here demonstrate the direct influence of an opposing electric field on the degree of fiber alignment and control of fiber placement.