The production of high-strength mats from electrospun poly(p-phenylene biphenyltetracarboximide) nanofibers was described. The electric fields used for electrospinning are of the order of 200 kVm-1. Mechanical testing results indicate that the mechanical properties of the aligned, non-aligned, cured, and non-cured nanofiber mats are quite different. It was found that the high-performance non-woven mats made from aligned electrospun nanofibers have a tensile strength of 241 MPa, a tensile modulus of 5.8 GPa, and an elongation to break of 5.2%.