Shear nanospinning utilizes the shear-driven extension of polymer solution droplets in fluid flow to fabricate nanomaterials. By using this process invented in the Velev group at NC State University, we fabricated fibers with micron and sub-micron sized diameters. The sizes, morphologies, and drug release characteristics of these fibers are influenced by many parameters, including polymer concentration, polymer molecular weight as well as antisolvent concentration. To examine the effect of the process parameters on the nanofiber size and morphology, polystyrene fibers were prepared using solutions that contained various concentrations of the polymer. These fibers were then observed under a scanning electron microscope to view changes in size and cross-section shape. Poly(lactic acid) fibers containing the model drug rifampicin were also prepared from varying polymer concentration solutions. Immersing these fibers in a Tris-HCl buffer solution with Proteinase K facilitated the release of the drug from the fibers, while the amount of drug released was monitored over time. The results suggest that the polymer concentration in solutions used in the process strongly affects the size and morphologies of the resulting fibers. Future research will reveal the drug release dependence on the size and morphologies of the fibers.