Resistive switching is demonstrated in diodes based on spin-coated layers of nanoparticles of Al2O3, CeO2, TiO2, ZrO2, Y2O3, or ZnO and a semiconducting polymer sandwiched between two electrodes. Inclusion of the metal oxide nanoparticles results in nonvolatile electronic memory characteristics that are similar to those observed for the corresponding “bulk” oxide. The major difference is that the nanoparticulate layers do not require a forming step. ZnO and TiO2 can be switched between a high and low resistance state using voltages pulses of opposite polarity, and Al2O3, CeO2, ZrO2, Y2O3 can be switched with both bipolar and unipolar voltage pulses.