We report on the network characterization of a series of hybrid nanocomposites consisting of integrated anisotropic nanoparticles (NPs) within a polyurea elastomeric matrix with low weight fractions ranging from 0.3 to 1.2 wt%. The grafting method employed to incorporate the silica-coated spindle-type hematite nanoparticles (SCH NPs), promotes the stability of the NPs in dispersion, and further enables their integration within the elastomeric polymer matrix, where the NPs are acting as multifunctional chemical crosslinkers and reinforcing fillers. The mechanical properties of these nanocomposite materials have systematically been investigated for both small and large deformations as a function of the particles concentration in the matrix. The results indicate that significant reinforcement of the hybrid nanocomposite is achieved even at very low NP loading with respect to the pristine elastomeric matrix. (C) 2013 Elsevier Ltd. All rights reserved.