The director was speaking at a panel for his new film You Will Meet a Tall Dark Stranger at the Cannes Film Festival.
"There's no advantage to getting older. You don’t get wiser. All that happens is that your back hurts more and you don't see so well. I would advise you not to do it if you can avoid it," the 75-year-old said.
When asked about his thoughts on death, Allen replied: "My relationship with death remains the same. I'm strongly against it."
He also described life as "a grim, painful, nightmare experience".
You Will Meet a Tall Dark Stranger, starring Anthony Hopkins, Josh Brolin and Naomi Watts, opens September 23 in US cinemas.
> Click here for our Cannes review of the movie