Water-insoluble nanofiber mats of synthetic polypeptides of defined composition have been prepared by a process involving electrospinning from aqueous solution. L-ornithine is a physiological amino acid. Fibers of poly(L-ornithine) (PLO) were produced at feedstock concentrations above 20% w/v. Applied voltage and needle-to-collector distance were crucial for nanofiber formation. Attractive fibers were obtained at 35-40% w/v. Fiber diameter and mat morphology have been characterized by electron microscopy. Polymer cross-linking with glutaraldehyde (GTA) vapor rendered fiber mats water-insoluble. The study has yielded two advances on previous work in the area: avoidance of an animal source of peptides and avoidance of inorganic solvent.