Resistive-switching random access memory (RRAM) devices are attracting increasing interest as a potential candidate for high-density nonvolatile memory devices. One of the main issues toward RRAM feasibility is the reduction of the reset current I reset necessary to restore the high-resistance state in the device. I reset can be reduced by controlling the size of the conductive filament responsible for the low-resistance state; however, available data only focus on direct-current reset analysis. This letter addresses I reset reduction under pulsed operation. Unstable reset behaviors, including set-reset and set instability, are shown to occur during relatively fast pulses and starting from set states with relatively large resistance values. These instability effects limit I reset reduction, posing a potential issue of minimum reset current achievable in RRAM devices.