Heinz Kähler studied classical archaeology and art history at the university of Freiburg in Breisgau.
Afterwards, he was assistant to the Archaeological Seminar of Ernst Buschor at the University of Munich (1937–41) as well as in its museum of casts.
His work on the Arch of Constantine in Rome (1953) and the Temple of Fortuna Primigenia of Praeneste (1958), both were completed at Saarbrücken.
He co-founded with Jacques Moreau the Monumenta Artis Romanae series of publications, writing personally the volume on the statue of Augustus from Prima Porta (1959).
At Cologne he authored his major work, Rom und sein Imperium (1962), which was translated into English in 1963 and became a widely used text for Roman art.