Method of detecting a pixel defect

A method of detecting a pixel defect for detecting a defect of a pixel including first to fourth transistors, connected to a data line, and receiving a scan signal and an initialization control signal includes turning on the first through fourth transistors by changing the scan signal and the initialization control signal to have a turn-on voltage level in an inspection period, detecting an inspecting current flowing in a path corresponding to the first through fourth transistors using a current detector that is connected to the data line, determining that a threshold voltage of the second transistor is within a normal range when the inspecting current is within a reference range, and determining that the threshold voltage of the second transistor is out of the normal range when the inspecting current is out of the reference range.