Foster, who found fame as a child star, decided against a movie career aged 13 - until Scorsese persuaded her to star as a child prostitute opposite Robert De Niro.
And the actress, who has since won two Oscars, is thrilled she didn't turn her back on Hollywood.
She says, "That movie was a big eye-opener, I'd thought acting was unimaginative stuff. You know, somebody gives you a script and you say it as naturally as possible. It didn't seem like a very challenging profession to aspire to.
"Then on Taxi Driver, for the first time, I was asked (by Scorsese) to create a character, and working with Robert De Niro, I suddenly felt like I was doing something really significant.