Recent work devoted to the study of photo-double-ionization of atoms is reviewed. This process is of much current interest because it is completely dominated by electron-electron correlations. In particular, experimental studies based on the techniques of low energy electron spectroscopy are described in the region near the double ionization threshold, together with (γ, 2e) coincidence experiments performed above this threshold. By using selected examples from non-coincidence and coincidence experiments the various kinds of dynamic and spectroscopic information that can be obtained are illustrated. Recent results, mainly in the rare gases, are described and their interpretation discussed. Future perspectives are considered.