An organic light-emitting diode (OLED) display device includes a display panel including a plurality of pixels, the plurality of pixels being grouped into a plurality of pixel blocks, a nonvolatile memory configured to store previous accumulated block degradation information for the plurality of pixel blocks up to a previous driving period, a controller configured to calculate current block degradation information for the plurality of pixel blocks in a current driving period, to calculate current accumulated block degradation information for the plurality of pixel blocks up to the current driving period by adding the current block degradation information to the previous accumulated block degradation information in response to a power control signal indicating a power-off, and to determine whether a sensing operation for each of the plurality of pixel blocks is to be performed by comparing the current accumulated block degradation information for each of the plurality of pixel blocks with a sensing reference degradation amount, and a sensing circuit configured to selectively perform the sensing operation for each of the plurality of pixel blocks.