According to Official Guinness Records,
The longest career as a theatre director of the same production is 40 years 7 months and was achieved by Vado Souza (Brazil) in his one-man show "O Navio Negreiro" from 23 October 1971 to May 2012. A certificate was presented to Vado after a special performance at Churrascaria Vento Haragano, São Paulo, Brasil, on 17 May 2012.
For a complete list of 2012 records, please visit 2012 Guinness Records in Brazil.