In a previous NMR study [Gonzalez, C.E.; et al. J. Chem. Phys. 1998, 109, 4670] we observed that the H-1 and H-2 spectra of both surfacted and ionic ferrofluids are broad and asymmetric. In ionic ferrofluids, this effect could be due to (i) electric interactions between the electrically charged magnetic grains and the electric dipole moments of water molecules and/or (ii) the interaction between water molecules and the distribution of magnetic field gradients in the intergrain volume. In this work we study a series of ionic ferrofluids prepared at different magnetic grains concentrations and with different surface charge densities. Our experiments clearly show that the sign and the density of the electric charge of the magnetic grains have no influence on the NMR spectra. On the other hand, spectral widths increase with the magnetic grains concentration, all the samples being far from the motional narrowing regime.