A security light is provided comprising a mounting base for attachment to a support therefor; sensor means on the mounting base for detecting the presence of a person or moving object within a radial range of the sensor means and within any one of a plurality of angularly adjacent sectors radiating from the mounting base that together cover an angular field of operation of the security light. A light source and reflector assembly has an angular field of illumination at least equal to the angular field of each of the angularly adjacent sectors and is angularly movable relative to the mounting base between a plurality of positions corresponding to the plurality of angularly adjacent sectors so as to be selectively directed in a direction in which the field of illumination covers an entire sector. A stepper motor is provided for rotating the light source assembly between said possible positions in response to activation of the sensor means associated with a particular one of the adjacent sectors and an associated microcontroller that is connected to said sensor means is programmed to cause the stepper motor to receive a required number of electrical pulses to move the light source assembly angularly, as may be necessary, such that it becomes directed towards a sector in which the sensor means detected the presence of a person or moving object.