Disclosed are a brightness control apparatus and method for a video display appliance that can lengthen the lifetime of a lamp and reduce the power consumption of the lamp by automatically entering into a lamp power saving mode if a display brightness is manually adjusted below a predetermined brightness value. The brightness control apparatus includes a memory for storing various kinds of menus for controlling an operation of the appliance, a display unit for displaying the menus stored in the memory and a video signal, a control unit for operating to automatically switch a present mode over to a lamp power saving mode according to a result of comparing a display brightness value being adjusted by a user with a reference brightness value pre-stored in the memory if the user selects a menu for adjusting the brightness from the menus being displayed on the display unit, and a lamp driving unit for driving a lamp according to a control signal output from the control unit.