A display device and a driving method thereof is disclosed. In one aspect, the display device includes: a display panel including a plurality of pixels, a plurality of gate lines arranged in a column direction, and a plurality of data lines intersecting the plurality of gate lines; a data driver transferring data voltages to the plurality of data lines; a gate driver transferring gate signals to the plurality of gate lines; and a signal controller controlling the data driver and the gate driver. The signal controller includes: a vertical boundary detector determining whether a first pixel among the plurality of pixels is positioned in the vicinity of a boundary region of an image pattern based on an input image signal for the first pixel; and a first adjuster adjusting an image signal of the first pixel based on an image signal of a second pixel positioned in a row previous to the first pixel and the image signal of the first pixel to output an adjusted image signal, in the case in which it is determined by the vertical boundary detector that the first pixel is positioned in the vicinity of the boundary region of the image pattern.