A circuit and method for controlling the brightness of a display screen implemented using a flat panel field emission display (FED) screen. Within the FED screen, a matrix of rows and columns is provided and emitters are situated within each row-column intersection. Rows are activated sequentially and separate gray scale information is presented to the columns. When the proper voltage is applied across the cathode and anode of the emitters, they release electrons toward a phosphor spot, e.g., red, green, blue, causing an illumination point. The present invention includes brightness control circuitry positioned across the row drivers for altering the applied voltage to the rows causing a change in brightness cross the FED screen. The applied voltage can be pulse width modulated or amplitude modulated to alter the brightness of the FED screen. Because the relative column voltages remain constant within the present invention, gray scale resolution is not compromised as brightness is altered. Within one FED screen implementation, it is more efficient to alter the row voltage; however, in an alternative embodiment of the present invention the column voltages are modulated in amplitude or pulse width to alter the brightness of the FED screen. The brightness circuitry of the present invention can be made responsive to a manual brightness knob or can be responsive to an ambient light sensor.