In this paper, we report the effect of the electron beam irradiation on various display parameters (threshold voltage, anisotropy of the relative dielectric permittivity, splay elastic constant, switching voltage and hence, steepness of the transmission voltage curve) of a room temperature twisted nematic display material, namely 4-(trans-4'-hexylcyclohexyl) isothiocyanatobenzoates (6CHBT). It has been observed that various display parameters of 6CHBT improve significantly up to an optimum dose of the electron beam irradiation, whereas further higher doze of irradiation causes deterioration. UV-Vis and Fourier transform infra red (FTIR) spectroscopy have been used to estimate the changes at molecular level responsible for the change in the bulk properties of the sample.