Abstract: An aiming device for a firearm comprising a laying device adapted to be fitted on the firearm parallel thereto, a laser device and a power supply. The laying device has a double articulation on which the front part of the laser device is mounted, and an adjusting facility having an articulation and a vertical rod, the bottom part of the laser device being retained on the facility for movement in two directions, so that vertical and lateral drift can be adjusted for by means of two adjusting mechanisms.The power supply comprising at least one battery is for energising the laser device and is disposed therein or outside it.