A pixel of an organic light emitting diode (OLED) display device may include an organic light-emitting diode; a first transistor configured to control, in response to a voltage of a first node, current flowing from a first driving power source to a second driving power source that is coupled to a second node via the organic light-emitting diode; a second transistor coupled between a data line and the first node, and configured to be turned on when a first scan signal is supplied to a first scan line; a storage capacitor coupled between the first node and the first driving power source; and an auxiliary capacitor coupled between the first driving power source and the second node.