An isocyanate-terminated polyoxytetramethylene (IPOTM; MW= 1350 g/mol) was used to modify silica nanoparticles (SNPs). The nanoparticles were spherically coated by an organic shell consisting of the polyether material with 55% by weight, according to thermogravimetric analysis (TGA). IPOTM diisocyanate, as a telechelic prepolymer, was also used for the preparation of polyurethane elastomers (PUEs) through polyaddition reactions with 1,4-butane diol in the presence/absence of IPOTM-modified SNPs. The elastomers were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and field emission-scanning electron microscopy (FE-SEM). Despite the use of the low amounts of the organically modified filler (5.0 and 7.0 wt.% of OSNPs), a significant enhancement in the storage and loss moduli (E’ and E” values) of the elastomeric films could be occurred. Also, according to the tan δ vs temperature graphs obtained from dynamic mechanical analysis (DMA), the IPOTM-modified SNPs led to a little decrease, up to 5°C, in the glass transition temperatures (T_g values) of the elastomers. In addition, TGA thermograms showed that no reduction occurred in the thermal stability of the elastomeric polyurethanes after the addition of IPOTM-modified nanoparticles.