The structure and electrical properties of phosphatidic acid (PA) Langmuir-Blodgett (LB) films adsorbing cyanine dyes (NK-3) with sandwich electrodes are investigated. PA LB monolayers adsorbing the dyes and the monolayers of Cd salt without the dyes are deposited using the subphases, containing various concentrations of the dyes and containing CdCl2 instead of the dyes respectively. Thermally stimulated current (TSC) measurements are used to examine the dipolar polarizations in the PA LB films, in the temperature region between 100 and 300 K. A marked increase in TSCs is observed above 180 K and especially above 250 K for the devices containing the dyes. The TSCs are caused by the dipolar polarizations, and the TSCs increase with increasing quantity of the dyes contained in the LB devices. Conduction currents are also measured at room temperature for the PA LB film devides. Increases in the conduction currents are also observed in the LB films containing the dyes. Furthermore, the conduction currents markedly increase when using the upper Au electrode. The current I vs. voltage V properties nearly follow the Schottky-type relation log I is-proportional-to V 1/2 . However, the conduction currents are very complicated, and this is thought to be due to composite mechanisms in the film and at the interface. The results are useful for applications of ultrathin film devices in the future.