The dielectric properties of pure and yttrium-doped PbS nanoparticles synthesized by the coprecipitation chemical synthesis route have been studied by several characterizations. X-ray diffraction patterns of samples were employed to estimate the crystallite sizes and intrinsic microstrains using Williamson-Hall (W-H) plot analysis. The crystallite size and intrinsic macrostrain values were evaluated in the range of 13.7-15.9 nm and 1.09 x 10(-3)-1.72 x 10(-3), respectively, using W-H plots. The formation of nanoparticles, nanoflakes, sponge, and nanosheets were seen via scanning electron microscope (SEM). Energy dispersive spectroscopy (EDS) of 5.0 wt% confirms the Y: PbS sample elements' chemical composition and stoichiometry. The optical band gaps increase in the range of (0.93-1.17 eV) with an increase in the dislocation density. The higher values of dielectric constant (23.6-28.0), dielectric loss (37.6-176.8), loss tangent (2.7-8.6), and electrical conductivity [10.2 to (11.7) S/m] have been reported at the lower frequency. The highest electrical conductivity values were obtained in the range of [4.71 to (4.81) S/m] for as-prepared samples. The greater capacitance and impedance values were found at 3 kHz and decrease with increasing the frequency up to 10 MHz. The current-voltage characteristic curves of undoped and Y: PbS NPs were performed under biased voltage. The space charge current density was noticed in the range of (8.7 x 10(-4)-4.2 x 10(-4) amp/cm(2)) at 1.0, 2.5, and 5.0 wt% of Y: PbS samples. The enhancement in the optical band gap and dielectric and electric properties on yttrium doping in PbS compared to pristine PbS NPs makes them suitable for optoelectronic applications.