Abstract: An apparatus for optically sensing obstacles in front of vehicles within a monitored sector, comprising a scanner disposed on the vehicle, which moves a narrowly focused beam of light pulses as well as the viewing direction of a light receiver in a rotation plane that is essentially horizontal, and an analyzing device which measures the profile of obstacles in the rotation plane from the angle and transit time of the pulses, is characterized in that the beam is moved in a 360.degree. circle and in that at least one planar mirror is disposed next to the scanner, in the rotation plane, outside the monitored sector, so as to reflect the beam into the monitored sector.