This work attempts an estimation of partial discharge inception and extinction voltages (PDIV and PDEV) of sheet samples of solid dielectrics due to void inclusions of different sizes using an ANN. The effect of void dimensions and also the dielectric thickness of three common insulating materials, namely, Leatherite paper, polyethylene film and Perspex sheets on PDIVs and PDEVs are examined. Further, the effect of the permittivity of the insulating materials is also examined.