Born on 29 November 1906 in Rome, Aldo was the first child of Alfredo Calo, MD and Ida, nee Ottlenghi. He obtained the 'Maturità' Classica', equivalent to a BA degree, from the Liceo Ginnasio Ennio Quirino Visconti in Rome before qualifying MD from the Facolta di Medicina e Chirurgia, R Università di Roma. He worked as an assistant surgeon at the Clinica Chirurgica in Rome before moving to England in 1938. In England he worked at various times in Leeds, Greenwich and Cambridge. From 1943 to 1946 he served in the RAMC reaching the rank of Major as a surgical specialist. After the war he was appointed a surgical registrar at King George V Hospital, Ilford. He obtained the FRCS in 1950, and was subsequently appointed senior lecturer and surgical tutor at St Bartholomew's Hospital, a position that he held until retirement. He published several papers on peripheral vascular surgery in the *Lancet*, *British medical journal* and other periodicals. His interests apart from surgery were music and golf. He was married in 1942, but there were no children. He died on 29 December 1977.