The objective of this study was to prepare and characterize electrospun SiO2 nanofibers for composite (particularly dental composite) applications. We investigated (1) tetraethyl orthosilicate (TEOS) as the alkoxide precursor, (2) polyethylene oxide (PEO) and polyvinyl pyrrolidone (PVP) as the carrying polymers, (3) several solvents for making the spin dopes, and (4) the morphological and structural properties of the electrospun SiO2 nanofibers and their relationship with the pyrolysis temperatures. We also investigated the morphology durability of the prepared SiO2 nanofibers by subjecting them to vigorous ultrasonic vibrations. The results indicated that the uniform (beads-free) amorphous SiO2 nanofibers with an average diameter of approximately 500 nm were successfully prepared. These SiO2 nanofibers also retained their overall fiber morphology when subjected to vigorous ultrasonic vibrations. The electrospun SiO2 nanofibers were, therefore, nano-scaled glass (amorphous SiO2) fibers, and could be used for reinforcement of dental composites.