A display apparatus having a display to display a picture, including an input unit, a data operator, a storage unit to store data about a gamma curve to be applied corresponding to an average input brightness of an input video signal, an auto-adjuster to adjust a position and a definition of the picture being displayed on the display, a gamma adjuster to adjust an output brightness of the picture being displayed on the display, and a controller to control the data operator to calculate picture adjustment data about optimum position and optimum definition based on synchronous signals and the input video signal when the input unit generates an input signal, and controlling the data operator to calculate the average input brightness of the input video signal and the gamma adjuster to adjust the output brightness of the picture on the basis of the data about the gamma curve to be applied corresponding to the calculated average input brightness from the storage unit while controlling the auto-adjuster to adjust the picture with respect to the picture adjustment data. Thus, a display apparatus and a control method thereof are provided, in which a gamma adjustment is implemented while an auto-adjustment is implemented.