This article reports on the piezoresistive behaviour of polymer-based nanocomposites, which are composed of epoxy resins and Pluronic-wrapped carbon nanotubes. The samples were prepared with carbon nanotube concentrations up to 1 wt.%. Good carbon nanotube dispersion was achieved due to the Pluronic wrapping of the carbon nanotube, as confirmed by electron and atomic force microscopies. The correlation between the electrical resistivity and mechanical strain was obtained for varying mechanical deformation. The electrical response is linear for small strains, and the values of the gauge factor are ∼2.6. The small variations of the signal over 32 cycles, the time response to deformations from 0.1 to 50 mm min⁻¹ and the stable temperature behaviour up to 60°C show the viability of these materials to be used as piezoresistive sensors.