On average, atmospheric absorption at OHP is roughly twice that seen at the European Southern Observatory (ESO) at La Silla, Chile.

Michel Mayor and Didier Queloz discovered the planet orbiting the star 51 Pegasi from observations made using ELODIE on the 1.93 m telescope.

It is now equipped with a direct charge-coupled device (CCD) camera at the f/6 Newton focus and is mainly used for studies of variability of X-ray sources, imaging of galaxies and H II regions and astrometry of faint solar system objects.

The 0.80 m telescope was first used during site testing at nearby Forcalquier in 1932 before the construction of the observatory, where it was later moved in 1945.

While primarily an astronomical research facility, the observatory also hosts two geophysics research stations, one studying the mesosphere and thermosphere, and one using lasers to probe the troposphere and stratosphere, studying aerosol and ozone content, using lidar techniques.