From 1958 to 1959 Regge held a post at the Max Planck Institute for Physics where he worked with Werner Heisenberg.

In 1968 he and G. Ponzano developed a quantum version of Regge calculus in three space-time dimensions now known as the Ponzano-Regge model.

In the mid-1960s he was approached by Radical period furniture manufacturer Gufram, for whom he "transformed a mathematical quartic function into a volume with intentionally ergonomic characteristics" to create the design for his 1968 Detecma seat.

[10] Married to the physicist Rosanna Cester, whom he met in the USA in 1954, the couple had three children, Daniele, Marta and Anna.

[11] The civil funeral rite took place in the Farewell Hall of the Monumental Cemetery of Turin, where the body was cremated.

[12] Along with Piero Angela, in 1990 he co-founded the CICAP, covering the role of scientific senior consultant in place of Edoardo Amaldi.