The effect of amount of clay content on the thermomechanical and electrical properties of epoxy/organoclay nanocomposites is investigated in the present research. An organoclay, cloisite 30B (C30B), was dispersed in the epoxy resin and was cured with an amine curing agent. The morphology of the nanocomposite examined by X-ray diffraction shows exfoliation for nanocomposites with lesser clay content and intercalation for nanocomposites with higher clay content. The storage modulus (E') of the nanocomposites increases monotonously with the increase in the amount of clay. The short time alternating current breakdown strength of the nanocomposites increases by the addition of C30B up to a certain clay content and then show a decrease. The space charge measured by pulsed electroacoustic method shows that the nanocomposite accumulate a very less amount of space charge and the charge decay in the nanocomposites are quicker than in the pure polymer. POLYM. ENG. SCI., 2012. (C) 2011 Society of Plastics Engineers