The actor was going through a slump for several years before the director cast him as hitman
Vincent Vega in his critically acclaimed crime movie Pulp Fiction, which was released in 1994.
Travolta, 59, can't thank Tarantino enough for choosing him for the highly coveted role - for which he earned a Best Actor Oscar nomination.
Speaking on Sunday night at his A Conversation with John Travolta Q&A session at the Theatre Royal in London, he said: "There were people who were much hotter than me who wanted the role ... But Quentin put his career on the line and refused to make the movie without me in it."
Travolta admitted the years preceding Pulp Fiction were a lean time for his career and he suffered a crisis in confidence in his on screen ability, despite his revered performances in movies such as Grease.
He added: "It got a little complicated for a few years. A lot of things added up to a five-year period that wasn't so good for me."
Apart from his Academy Award nomination for Pulp Fiction, Travolta has only ever been up for an Oscar one other time - for his portrayal of Tony Manero in Saturday Night Fever - but he is not bitter about his lack of recognition.
Being quizzed by host Barry Norman, he said: "I don't feel at all ignored or not verified. You're not going to find a bitter guy in me."
At the end of the event - which also saw the Hollywood star take questions from fans - Travolta was presented with an airplane-shaped birthday cake ahead of him turning 60 on February 18.