He was appointed a lecturer at the TU in 1955 and, in 1957, professor and then, in 1959, C4 professor.  In 1964 he took the Chair of Inorganic Chemistry at the TU.
In 1964, he was elected a member of the Mathematics/Natural Science section of the Bavarian Academy of Sciences. In 1969 he was appointed a member of the German Academy of Natural Scientists, Leopoldina and in 1972 was given an honorary doctorate by the Faculty of Chemistry and Pharmacy of the University of Munich.
He lectured across the world on metal complexes of cyclopentadienyl, indenyl, arenes, olefins, and metal carbonyls. In the 1960s his group discovered a metal alkylidene and alkylidyne complexes, since referred to as Fischer carbenes and Fischer-carbynes.  Overall he published about 450 journal articles and he trained many PhD and postdoctoral students, many of whom went on to noteworthy careers.  Among his many foreign lectureships, he was Firestone Lecturer at the University of Wisconsin–Madison (1969), visiting professor at the University of Florida (1971), and Arthur D. Little visiting professor at the Massachusetts Institute of Technology (1973).
He has received many awards including, in 1973 with Geoffrey Wilkinson, the Nobel Prize in Chemistry for his work on organometallic compounds.