A projection display apparatus with a light source, a light valve and an optical system for projecting an image formed in an image-forming plane of the light valve onto a screen is disclosed. The projection display apparatus includes a first processor for calculating an area of an image projected onto the screen, a photometer for measuring illuminance in the neighborhood of the image projected onto the screen, a second processor for calculating a black-level correction value from the area of the image calculated by the first processor and the illuminance measured by the photometer, and a light-source-power controller for controlling power supplied to the light source on the basis of the black-level correction value calculated by the second processor.