Abstract: A projector desk lamp employs a base for supporting components of said desk lamp on a flat surface. A stem with one end forming an adjustable articulated joint with said base that can be swung between a horizontal position and a vertical position freely and can be locked in intermediate positions. A lock knob mechanism is used for quickly releasing and locking said stem during adjustment. A bracket is formed on the other end of said stem. A lamp head which is adjustably articulately joined by said bracket can be swung in more than 180 degrees and can be locked in intermediate positions. A lamp head comprises a bulb, a reflector, an adjustable lens assembly and a disc-shaped slide. Therefore, this lamp can be used as a projector for enlarging images of the slide projected on any surface with a selectively adjustable ratio. It can also be used as a desk lamp to illuminate an area with adjustable beam-angle and brightness.