The photosensitizing behaviour of 2-imidazolin-5-one, which was studied earlier at sprayed ZnO thin film electrodes, has been reinvestigated at nanocrystalline ZnO thin film electrodes prepared by the sol-gel method. By using semiconductor electrodes in the form of nanocrystalline thin films, all PEC cell parameters such as dye-sensitized photovoltage, photocurrent and IPCE were found to be higher as compared to those obtained with the use of sprayed thin film electrodes. Thus, through this investigation it has clearly been demonstrated that the same dye can perform better on nanocrystalline than sprayed thin film electrodes of the same semiconducting material.