Now 98 years old, he is still working and opens his surgery in the Paris suburbs two mornings a week for patients, some of whom he has treated for decades.
With no health woes of his own - he doesn’t even wear glasses during his consultations - Chenay said a quiet retirement had no appeal.
"If you’re over 60 they put you with the old people. One day you’ve got cards, the next day bingo, then there’s sudoku... With all that you become a complete idiot. I’m better off being a doctor!"
Originally from Angers in western France, Chenay worked as a welder before becoming a doctor, ultimately qualifying as a radiologist before moving back into general practice.
His surgery does not look high tech - there is a fax machine but no computer on the desk - but Chenay says he keeps up to date with all the latest developments via his subscriptions to online medical journals.
He says a new development in his nearly seven-decade career is patients who erroneously diagnose themselves on the internet and then turn up at his surgery demanding drugs.
Many of his patients say they struggle to get appointments in Chevilly-Larue, which has three doctors for a population of 19,000, so they queue early to see Chenay who runs a drop-in surgery, promising to see the first 20 patients who sign up.
"(In France) we have the doctors, we have the sick people, but to bring the people together is really not easy," he said.