The actor, who plays android David in Prometheus, admitted that he was very nervous before filming the sci-fi epic, but Scott quickly put him at ease.
"It was a lot of fun. I was pretty nervous, on the first day; I didn't know what to expect. Then it just became like play really," Fassbender revealed, reports Flicks and Bits. "Even though we were both very serious about the work, it was a joy."
Fassbender went on to describe Scott's much-discussed collaborative filmmaking style.
"No idea was stupid until we tried it and put it on the floor. If it worked it worked, if it didn't it didn't," he explained. "What's really impressive about Ridley Scott and watching him work, you've got 350 people on set, and each department has got to come and bring their top game to set."
The actor continued: "Seeing someone have involvement and instilling passion in each of those departments is pretty amazing to witness, and to have the precision in each department, and to have the imagination, enthusiasm, energy... that's what sort of makes him the master, you know?
"You have to be a ringmaster, especially with something of this size, this magnitude."
Fassbender recently starred in a new Prometheus viral video, which featured his android character David ominously describing his many workforce skills.
Prometheus is scheduled for release on June 1 in the UK and June 8 in the US.
> Prometheus: Uncovering the truth about Ridley Scott's blockbuster
> Prometheus has more viral videos on the way, says Guy Pearce
Watch a trailer for Prometheus below: