An organic light emitting diode (OLED) display is provided. The OLED display includes a display panel including pixels formed at each of crossings of a plurality of gate lines and a plurality of data lines, a monitoring signal line formed along an outer area of the display panel, a first signal supply unit that supplies a monitoring signal to the monitoring signal line and generates a first power control signal, a power supply unit that supplies a high potential driving voltage and a low potential driving voltage to the pixels, and a second signal supply unit that monitors the monitoring signal and generates a second power control signal. If the monitoring signal is not monitored, the second signal supply unit controls the power supply unit through the second power control signal and allows the power supply unit to stop supplying one of the high and low potential driving voltages to the pixels.