Poly(2-oxazoline)-based biomaterials have shown significant potential for various applications in the past decade. Herein, we present a methodology for the design of degradable diselenide-cross-linked nanofibers by aqueous electrospinning of selenol (SeH)-modified poly(2-ethyl-2-oxazoline) (PEtOx). The selenol groups have been introduced into PEtOx by reacting partially hydrolyzed PEtOx (poly(2-ethyl-2-oxazoline-)-co-ethylenimine (PEtOx-EI)) with gamma-butyroselenolactone, whereby ring-opening upon reaction with the secondary amine groups in the polymer backbone yields selenol side chains. Subsequent aqueous electrospinning of the selenol-containing PEtOx was linked water-stable nanofibers, ascribed to the formation of diselenide cross-links. The effects of changes in the experimental parameters and the influence of the selenium content on the electrospinning process were investigated in detail. Dynamic exchange between the remaining free SeH groups and diselenide bonds formed upon cross-linking enabled a tunable dissolution of the PEtOx-based nanofibers, which could be controlled by changing both the temperature and cross-linking density. Furthermore, the dissolution of the diselenide cross-linked nanofibers could also be induced by the exchange of diselenide groups under ultraviolet (UV) irradiation.