We present a single-step route for the preparation of crosslinked poly(vinyl alcohol) (PVAL) nanofibers where a conventional electrospinning setup can be used. The simple crosslinking chemistry and the fast and easily applicable technique is an important step towards large-scale production. In contrast to conventional systems, the PVAL crosslinker solution exhibited no increase in viscosity during storage and can therefore be used even after long shelf-times before electrospinning. In addition, the crosslinked nanofibrous mats exhibited a gel content of almost 100%, indicating complete crosslinking; they did not dissolve in water, and no PVAL was found in the aqueous extract. The E-moduli of the nanofibrous mats before and after water immersion could be measured by an intermodulation atomic force microscopy technique. A denser nanofibrous texture with enhanced mechanical properties can be observed after long-term water immersion.