Solid dispersions of ketoprofen in nanofibers were prepared using electrospinning process with polyvinylpyrrolidone as the filament-forming polymer. Results from differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and fourier-transform infrared suggested that ketoprofen was well distributed in the polymer nanofibers in an amorphous solid dispersion state due to the hydrogen bonding between them. In vitro wetting and dissolution tests showed that the nanofibers could absorb water from the wet papers and wetted within several seconds, and ketoprofen could be exhausted within 30 seconds. Electrospinning is a useful process for the preparation of solid dispersions.